BT run several customer facing WiFi systems they include a subscription with their broadband services (it also means customer routers have a separate "public" connection for others to use if subscribed) my problems, are not just co-channel interference, but the fact I am close enough to suffer receiver desensitisation or the relatively simple ZigBee receivers. I am aware, me adding three ubiquiti adds to the WiFi soup, but I "can" get the WiFi to work! Especially on 5Ghz! I "can't " get ZigBee to work reliably with, or without my WiFi.
The signal level of the BT system is still stronger, than my home WiFi! That's some feat given RF level falls at a square law relative to distance! The whole Chinese server thing, really? I would worry more about my government than the Chinese!! They know who I am! The primary downside of network based lot seems to be the possibility of it being hacked and used for a ddos attack or something similar, that is why I don't use my ISP supplied router modem, the increase in the speed of our connections has way outpaced the improvements in the security of cheap devices! If you worry about Chinese servers,go look at your modem/router, if "anything" has real access to your network, it is that!!
Honestly, ZigBee might be perfect for some people, my only concern is You test before buying a load of it!! Oh! And look at your microwave oven LOL, you would be surprised by how many people's ZigBee and WiFi intermittent problems are caused by a microwave oven lol! They "All" leak, and looking at one on a specrum analyser, would scare the bejesus out of you!!
Love and peace
Garry
Most people reading here understand the risks, security requirements, flash firmware, can code etc.
This YouTube video is just designed to stir the pot and generate clicks.
The problem is that your average user watching this video and not understanding the risks of wifi can become another useful idiot in some bot net.
Yeah, that makes sense then. BT was probably all you really needed to say! 
You're basically in an environment where the front end of the Zigbee receivers are getting saturated by all the WiFi side lobes. nice. Thanks BT!
It's unfortunate, as Zigbee can coexist with WiFi quite well.
Sometimes you just can't solve for the environment.
I expect if I were to look at my Microwave with a spec an, I'd probably see a hell of a lot of LO energy and its harmonics. But I'd also posit that the dangerous wavelengths are both massively attenuated, and reasonably well filtered. But in the interest of maintaining my ignorance on such things, I'll pass on looking at it in a spectrum analys/zer.
S.
I am a recently retired IT and physical security manager, so I have a bit of knowledge and expertise on security. The biggest vulnerability for IOT is mostly on the manufacture. This is especially true for IP cameras. Corporate and consumer products that have no or complicated firmware and software update mechanisms or allow no or weak passwords are the main reasons those devices were compromised in the first place. Yes, Chinese manufacturers were guilty as well as Japanese, Korean, European and American companies.
This has changed quite a bit in the corporate market and is starting to change in the consumer space. Embracing security is a requirement to do business in most markets now.
YF
Interesting...
Bigger question is, are you happy to finally be retired from IT? 
Hi there @YapFlapper!
yes, I agree, things are slowly getting better, but a lot of people here keep their Modem/Router for the life of the contract, many years, and seem to stick to the default admin and WiFi passwords, worse still often there is a simple way to work out the default WiFi password from the SSID
as you say, it's getting better, it's just that more time is being spent writing new malware than educating end users!
I don't believe the Chinese are significantly worse, or better than manufacturers from other places
it took me enforcing security in our email suite just to force our users to use a lockscreen on their phones, they are that lazy and uncaring!! security needs to be strong by default 
users rarely want it
love and peace
Garry
Yes! Gives me time to finally jump on all those Honey-Do projects. I also get to slip in a few of my own projects (Honey-Don'ts).
YF
I hear you here you bud!!
I’m not picking a side here i’m just stating facts for my case. My wife is restricting me from throwing money into anymore HA stuff as to all my purchases, but for me and i’m Just speaking for my situation the Wifi devices that I have are and have been 3 times more reliable then my zwave or zigbee devices and this is with repeaters in the mix. Just to give an example I have a zooz motion sensor that as of this moment is reporting motion as active all the time, my 2 door locks Kwikset 910 and Schlage B469 are doing what ever the hell they want after the last few updates so I can see where Paul Hibbert that’s the guy in the videos name is coming from.
And to get everything in balance I have no wifi HA devices and only z-wave and zigbee and have no trouble at all. I think it all depends on the situation etc. I do have some friends though that complained about wifi devices not getting an IP address. Apparently wifi devices are also sold to suckers who don't read up on how things work, because the lease time on there DHCP was set to two weeks and there ARP tables were completely full.
That is the problem with inexpensive consumer routers that promise whole house coverage. You get around 40 devices and they start to have issues. I paid a premium for my Orbi due to my large family size we have over 80 WiFi devices running concurrently. The only home automation device I have WiFi is my Ecobee thermostat. And the Hubitat is connected via cable. So far with the Orbi I have the main router in the middle of the house on the first floor , One satellite on the second flow, and the 3rd satellite in the basement. All the critical stuff has static IP's and is cabled to switches to the router. Last time I checked when we had the whole tribe home I had over 60 devices connect to the main Orbi on the first floor and I was still able to stream on my Roku's and XBoxes and no issues. As they say you get what you pay for.
With all due respect, you're kinda comparing apples and oranges. Your "wifi" devices are directly plugged into to AC power. which doesn't require the devices to "sleep" to conserve battery life. Devices that "sleep" (like your zooz sensor and locks) will always be less "reliable" than a device that is always on powered.
But having a solid zigbee and zwave mesh will eliminate the unreliability in battery powered devices.
And with all due respect to you, also not true I have a strong zigbee and zwave mesh and just as other people here on the forums can also speak to, that don't mean a hell of beans. I have 4 peanut plugs and 4 Aeotec plugs and I still have nothing but issues with my zigbee and my zwave sensors and locks the only reason I still have them is because i don't have a reliable way to intergrate them with my other things except for Ifttt the day HE has native wifi sensor intergrations those sensors are gone.
And yes I know I can put the zigbee and zwave sensors on seperate hubs but that is the point i am stressing I have several wifi plugs that just work i'm fortunate that my internet stays up 24/7 the last time it went down was 2 years ago when an idiot ran into the light pole on the main street and took it and our main box out for our neighborhood. But for zigbee and zwave I had to add extra expense to purchase 8 plugs to extend the mesh at a cost of $211. compared to 12 wifi plugs at a cost of $75 one of which I had to place on my HE hub just in case I had to do a hard reset which I have had to do 2 times already.
Point is you can have a strong mesh and zigbee and zwave still gives you problems because of other things house make up etc etc but for me and some others wifi is rock stable.
I live in an NYC apartment with literally dozens of neighbors within range and with 4 telecom wifi antennas outside my one glorious window sky facing window. I use zigbee no problem. I actually switched all of my wifi items to zigbee.
No hub required!*
*except when you start scaling you need to buy mesh wifi hub(s)
How many battery powered zwave and zigbee devices do you have?
Exactly why I won't buy any wifi devices, I even have Netgears X10 R9000 router (one of their high end) and after about 25 wifi connections the wifi radio completely disabled itself and the router had to be warrantied. I'll spend $10 more on zwave zigbee devices than $400 for more wifi routers.....
I have a total of 47 zigbee zwave devices 31 WiFi devices. Never had a problem out of any WiFi Device also should mention I have the net gear Orbi system and those 31 devices do not include 2 fire tv sticks 2 nvidia shields 1 mi box. We also have Directvnow and Netflix and stream all the time. And I have never had a WiFi device bog down or stop working. Also to mention I live in Ga with Charter internet 100 down 12 up.
Like I said I am always having a problem with my zigbee and zwave devices either I have to reboot the hub or due a zwave repair. But as I stated each persons situation is different. Just as an example about 2 mos ago I had an issue with 2 zwave door sensors they were reporting as opened and scared the freaking bageezies out fo my wife at 4am in the morning setting the damn house alarm off as a test a purchased 2 WiFi door sensors for those same doors 2 mos later 3 more problems with the zwave sensors 0 reporting issues with the WiFi sensors, but again my case and situation is different from others.
And again before I end this post my zooz ze18 motion sensor is still stuck as reporting active after 2 hub reboots 5 zwave repairs and a exclusion inclusion.
So that means you have 39 battery powered devices ran off of a total of 8 repeaters. If that is the case, I can promise you, you do not have "a strong mesh" it would also give a pretty good explanation to lack of device reliability. Zwave repairs will not fix this no matter how many times you try.
You have right at 6 battery powered devices per repeating device (if they were able to manually split their signals equally) I myself have 2 repeating devices for every battery powered device, and have no issues. Do you have to have that many no, will your 6 to 1 work occasionally yes reliably no as battery devices again have to be "woke up" and having a lack of repeating devices in the mesh sending the wake up command will show issues.
My setup is closer to @waynespringer79 than yours. I also live in the 'burbs - WiFi is not congested
My zwave and zigbee meshes are rock solid. WiFi is fine too, but I'd rather keep everything local.
