If anyone wants privacy while maintaing a smart home, then Home Assistant is the solution.
Its not adopted widely because it has a learning curve and it needs a bit (or a lot) poking around to make it work.
It also has a voice assistant that is not AI powered ( but it could be supplemented by a local LLM if you really want to).
A big rabit hole if anyone is interested to go to.

It’s not adopted widely because every single smart home device marketed to normies is infected with cloud bullshit. Go to Home Depot or whatever and look on the shelf: literally every single product will have “Works with Alexa,” “Works with Google Home,” and/or “Works with Apple HomeKit” badges stamped all over the package, but not a single one will mention a damn thing about Home Assistant even when the device actually is compatible. The closest you get is ones that mention “Matter” 'cause it’s at least supposed to be a standard, but it feels like it’s getting slow-walked harder than CableCard sometimes (and if you don’t remember how that worked out, the answer is “not well”).

I would almost call it a conspiracy against openness, but it’s really just the banal result of no rent-seeking leading to no excess profit to plow back into marketing… which is even worse.