Well, you still need a client if you're on mobile. I'm not going to watch my video essays through a browser if I can do it through an app. I use libretube which ends up being Piped under the hood, it's just smoother.
I also used to use revanced because it allowed me to keep a few public playlists up to date (something you can only do by interfacing with Youtube). People have their reasons for things.
Every time I click on a Piped link that has been posted here by the bot after someone posts a YouTube link, I just wait and wait for it to start playing. Eventually I run out of patience and click the YouTube link, which starts to play immediately.