Long ago, I saw a movie as a kid in the 1970s called Demon Seed, where this big computer gained consciousness and extended it's presence to a smart home (well, smart home with tech from the 1970s). It scared the heck out of me, even though seeing it now it's pretty tame...regardless of the whole impregnating a woman with it's child.
If you build new KNX is great. It works with Home Assistant and it's just a bus system. You program it once and it works for decades.
My main gripe with smart devices is their sketchy software that may or may not have vulnerabilities in them and may or may not be diligently updated with security fixes by the company that makes them. If I can concentrate most things to one device...like the AppleTV, which gets updates all the time...then I can isolate problems. If I have to worry about a myriad of things throughout the house, that's something else.
I live in a log cabin in the back woods with no thermostat, no doorbell (or even locks). No smart TV. Everything is as low-tech as possible. I have seen how the sausage is made.