Up until last month, I was doing this very thing leaning heavily on Homebridge plug-ins and Wink for the Z-wave stuff. Wink's pending implosion gave me an opportunity to step backwards, and clean up the HA mess that evolved over the past 5 years.
First task was to move all of my Homebridge plug-in integrations to my new HE. I then dumped the old/ancient Homebridge server, replacing it with a Docker running HOOBS (a Homebridge appliance) linked to the HE via Maker API. This made all of my HE devices/switches/contact sensors available to HomeKit.
I am using Siri and the iOS Home app as the primary user interface, for WAF and myself. Apple's setup is workable for a UI. Their presence sensing is also good, so I use that. No Alexa in our house, but we both have Apple Watches so Siri is on our wrists and just a push of the Watch crown away.
There are six automations still running on HomeKit:
One momentarily toggles a HE virtual switch when anyone arrives home, which triggers a change to "Home" mode on HE and does things like turn on the outside lights and unlocks the door.
One momentarily toggles another HE virtual switch when the last person leaves, which triggers a change to "Away" mode and does things like set the alarm system and turn off the outside lights.
The remaining four HomeKit automations are for handling a HomeKit front door lock on HE. There's a virtual switch on HE for the lock. Two automations lock/unlock the door if HE turns the virtual switch on/off. The second two automations turns that virtual HE switch on/off if someone locks/unlocks the door by code or manually, so HE knows the lock status by looking at the virtual switch.
HomeKit's automation rules can most certainly do most simple tasks, and I was happy with it for a few years before Wink's extortion email forced me to buy an HE. I also picked up three Inovelli Red switches, and they have spawned a whole slew of Button Controller and Simple Automation rules that I would have never imagined in HomeKit a month ago. For me, letting HE do the driving and using HomeKit for a voice/user interface and presence sensor makes the most sense.....