I have not tried out voyager, but just from looking at it’s GitHub, it’s essentially just a web browser packed in a native app anyways.
Performance shouldn’t really be different from browser app to local app this way unless something is done wrong, or there’s some specific functionality, like async I/o that’s still unsupported.
Notifications are also a thing in web browsers nowadays. Most device features that you can access in a separate app are actually supported by now.
I feel like that defeats the purpose of automated recommendations, since you can still search for the videos (that you want to watch) and create playlists either way.