Not a true alternative, but I love Freetube. Just for the fact that I don’t have to have an account tied to it with no ads and sponsor ads is nice.
Lately there’s been connection issues but usually gets resolved with 2-3 days.
Even works on my raspberry pi.
Typing this up on /e/os on OnePlus6t. Love it for ~2 years now. Signed up and support the project now with their ecosystem (64gb option).