Well not really though. Youtube in mobile browser is one of the few less cluncky websites. Native app might be better but youtube website is pretty good in mobile
Yeah, I'm not constantly on yt but nothing ever annoyed me with yt on Fennec, perfect basically (tho I kinda always prefer 'normal' UIs over apps with big buttons).
I also use the autoHD add-on bcs I'm not signed in ever.