BlockTube is a must - can block specific channels from showing up, videos with "Journaling" and "changed my life", hide videos watched over 50%, etc.

Enhancer for Youtube is also super useful: disable shorts entirely, autoplay next only on playlists, tweak number of videos per row, default playback speed, default theater mode, etc.

As another commenter said, Youtube is one of those sites that really requires multiple plugins to be useful :/