An a real alternative (not a front-end): Peertube.
Full disclaimer: I am the founder of Exquisite.tube.
If you do want a front-end: selfhost Invidious, Piped or Cloudtube. Might want to refrain from sharing it with too much people, as Google severely ratelimits it. It'll become a cat and mouse game before you know it (been there, done that, gave up).
but feels like if i'm looking for mainstream content (e.g. movie trailers) there isn't no second best. youtube is the only place
@hi I honestly found nothing :(
So I added some YT synchronisation (based on yt-dlp) to my Peertube instance just to watch things from there. But there are a few glitches so I’ll probably go back to deploying Invidious somewhere.