It can certainly break if YouTube changes something on their side, but I've never had huge issues, so it's probably not something that happens very often. But the mobile site is a good fallback option.
I do experience pretty regular issues, but in really specific areas: listening to long music playlists can get janky if they're left open across multiple days, sometimes videos stop working after that and I need to force quit and restart the app (I assume it's doing something to refresh some cookie or connection).
Mostly the benefits outweigh the downsides for me, for a lot of reasons: data export is a big one. The ability to download videos/audio is another. Background listening is another. It's also way more battery efficient than any of Youtube's official apps for video or music.
One thing I would recommend, the version in the offical F-Droid repo works, but you can also install the direct source in F-Droid, which will get updates/bugfixes much more quickly.
Plus if you install the direct source in fdroid, it's signed by the same key as the official releases, so if you don't want to wait for fdroid to update all the other random repos you're too lazy to remove, you can still update directly from the notification/app/website.
Mostly the benefits outweigh the downsides for me, for a lot of reasons: data export is a big one. The ability to download videos/audio is another. Background listening is another. It's also way more battery efficient than any of Youtube's official apps for video or music.
One thing I would recommend, the version in the offical F-Droid repo works, but you can also install the direct source in F-Droid, which will get updates/bugfixes much more quickly.