YouTube has been cracking down on alternative frontends.

Vanilla Invidious currently doesn't work well,
so most hosters paused and/or gave up.

Fijxu runs a fork of Invidious,
with their own modifications implemented to circumvent the blocks,
here's the source code if you're interested:
https://git.nadeko.net/Fijxu/invidious

I've got big respect for Fijxu,
he's been doing a very good job of keeping Invidious alive + fighting against the YouTube crackdown lately, basically all on his own.

If you can please consider:

• Donating for their work/hosting
• Hosting their fork on your own
• Solving open issues with pull requests to their fork

All the above can help Fijxu,
since currently he's mostly fighting a big tech giant all on his own.