That's something I want to get into. I want to set up that self hosted software, forget what it's called, but you can integrate with IoT devices just like you can with a mainstream assistant service like Google Home.
What I really want to do is automate my blinds, which are the chain loop type, so I can say "house, open the living room blinds" like they did in Smart House, the Disney channel original movie (or maybe that was Home Alone 4, but we don't talk about that one). I found a little motorized device that integrates with these chain blinds but it was a bit pricey. Of course if I tried to make it with my own Arduino etc it would be an ugly mess.