Currently Invidious won’t help and many other frontend (say Materialious) fails either. So is there still any way to access youtube videos (no matter frontend or download videos)?
LibreDirect lists a number of frontends that may be helpful. visit https://libredirect.github.io/ for detailed information.
I’m not sure I understand the problem and why you need an alternative front end. I have no difficulty accessing https://youtube.com (without logging in) and watching YT videos with Tor Browser. When navigating to a specific video URL (e.g via link) I have to solve a captcha, but that’s the only barrier. Can you provide an example of a video you can’t access?
Ah yes, you are quite right. The solution is just to select a New Tor circuit for the site (hamburger menu, instructions here). When the page refreshes you shouldn’t get the “Sign in to confirm you’re not robot” message. I use the keyboard shortcut and it’s become so automatic I had forgotten I do it! Sometimes you need to change circuit more than once, but I’ve never encountered a situation where doing so doesn’t work.