You are not wrong about HA still being in the early stages. But you’re misunderstanding Google Assistant Relay. You don’t need a Google Home device. You just need a Google account and the patience to follow the directions to build it. One it’s done, you have a great tool that can control all sorts of devices, and even control the SmartThings cloud (also no hub or history of ever owning one required). Totally transparent to your family. They will not be interacting with Google Assistant, the hub does.
So using a RM rule, I could tell Alexa to turn on a virtual switch, the virtual switch would tell Google Assistant Relay to turn on the Leviton switch. When I tell Alexa to turn OFF the virtual switch, the same RM rule would turn off the Levitown switch by telling Google Assistant, to tell Leviton to turn OFF the switch.
It sounds more complicated and slower than it actually is. It’s only seconds delay and very consistent. The reality is the industry is selling everybody these Wi-Fi switches because the general population understands Wi-Fi, and they don’t understand what Zigbee or Z-Wave is. So the market is flooded with these cloud connected Wi-Fi switches that top out at about 30 devices on most routers, because that’s all most can handle before other serious issue on your WiFi network.
Wi-Fi is the wrong way to go about home automation in my opinion. It doesn’t scale well, doesn't repeat to other devices, so it's a star topology only, and forces cloud dependency unless app/drivers a written to handle it. That’s no small feat, and these are not popular switches among the user base that is currently supporting the growth of this platform and of SmartThings. Other protocols are going to emerge that will probably take over from Zigbee and Z-Wave, but that’s very far off.
So for now this is how you get around this limitation of Wi-Fi plugs, switches and other devices.
Here’s an example of how I use Google assistant relay to make Alexa speak whatever I want when something happens on Hubitat. I know it can be slow with some services to control devices via IFTTT, and that is the reason that I like and promote the use of Google Assistant Relay so much. The Google cloud is rock solid and very responsive. If there’s a delay, it’s almost certainly going to be with Leviton or whoever's device your trying to control.
