I try to go that route, but for some items there isn't a good alternative. I have a Roborock vacuum which requires the app and an internet connection to use the smart features, but it can still be controlled by the physical buttons if the internet is down.
I'm hoping that Thread/Matter will change that, but most likely it'll still be the same walled garden - there are already some devices that use ZigBee but only work properly with their own hub.
I have a Roborock too. It has an app that shows you the map, collected by the vacuum's lidar, so that you can point the vacuum to a specific area on this map and stuff like that. I absolutely hate that I don't have control over what's actually being sent to the cloud. Though at the time of purchase there were no models with lidar that didn't require the Internet connection. Not sure if that's still the case. I would be happy to replace the damn thing with something that doesn't call home.
I'm hoping that Thread/Matter will change that, but most likely it'll still be the same walled garden - there are already some devices that use ZigBee but only work properly with their own hub.