This is a web extension addon that removes the more distractible parts of YouTube. This includes the homepage video suggestions, related videos, and all comments. But you can still go to a channel page and find videos that way, or explicitly search.
It is intentionally minimal so you can read it and install it yourself.
I don't know. Is it 38 lines of commented code? Maybe you should.
Pull requests welcome if it doesn't make the code any harder to review in 5 seconds.