For Firefox: uBlock origin (of course)

Privacy Badger - controls which sites are allowed to use cookies

Mind the time - tracks time spent on various Web sites

Video DownloadHelper - detects media and allows you to download and transcode it.

Bitwarden - password manager

I wonder what made youTube decide to fix this loophole? These days the vast majority of people use phone apps or smart TVs to watch. The number of people using Firefox plus ad blockers must be quite small and it’ll be a constant effort to keep updating their anti ad block algorithms.