But the use case is just to serve videos right? I know that new things will not come. But YouTube is almost the same in these 10 years I think.
But YouTube is also a very complex app. Yes it "just" exists to play videos, but the app is so much more than a video player. Browsing, searching, comments, chat, playlists, YT Live, subscriptions, profiles, ratings... there's a lot there.
Perhaps they could start with just cutting down their bloated 100x-duplicated 4MB CSS file?
However, it's clear that the devs are mainly composed of trendchasing sheeple who have drunk the Goog-Aid and are addicted to newness and reinventing wheels to make them square... because they have to justify their existence.