Try Unhook (desktop) and Untrap (iOS). At this point, my YouTube experience is just the channels I subscribe to, and the video player. It reduced my usage to almost zero.
I'm not exactly curing cancer, but my media consumption is more moderate and mindful now.
Same thing can be achieved (mostly) by disabling youtube watch and search history. It causes the home page to be blank, and all recommendations under any video are usually from your subscriptions, related your subscriptions, or directly related to the video.
This is the simplest and most effective solution, Cheers
Just add channels you like to your rss feed. It works great with freshrss.
Or if you want to get fancy use tubearchivist with the Jellyfin plug-in.
TIL tubearchivist has a Jellyfin plug-in. Cheers.