Depends on what features you need. For some people the whole idea is that you can take and make calls on your watch, as well as messaging. Sometimes the health tracking stuff requires a proprietary app instead of Gadget Bridge.

The most private watches are glorified notification machines. I got my wife a Garmin Venu and she uses their app. It's not perfect but they're fairly private as far as smart watches go. She needs all the bells and whistles so that's the best I was able to find that is high end.