Understood. As far as HomeKit support, I use
https://homebridge.io/ on a raspberry pi, which adds HomeKit support to devices that don’t have it. I am able to control my thermostat, Logitech harmony hub, and a couple of smart plugs that don’t natively support HomeKit. My goal in setting this up was to exclusively use the “Home” app on iOS and Siri for smart home control, and so far it’s been a success.
I’m no programmer, it was pretty simple to set up. But not everyone wants to deal with setting up homebridge, so admittedly using echo devices is more of a “it just works” way. Here’s hoping smart home standards continue to improve to where anyone can use whatever they want.