Yeah, came here to say this. The fediverse sites are so diverse that instead of trying to implement everything in one gigaapp it's better to just browse the site in the browser.
heck, most some of the sites even allow for installing it as an app. Kbin works pretty good and for lemmy I use wefwef.app which mimics Apollo layout and even have gesture based actions, only downside is that I'm using android and the iPhone app UX threw me off lol (like the no universal back button).
though I think OP wants something like one place to see everything, and seamless experience when visiting each server / site.