Google started to crack down on alternative frontends.
No youtube videos can be played now on cytube, and they made it hard for those who host invidious instances:
https://github.com/iv-org/invidious/issues/3822

Cloudtube is working. At least at the moment. Perhaps because it's small, but I highly doubt it Google doesn't know about it, so I'm expecting it going down.
Wat nau?