Recommendations are a killer feature on YouTube. Only, one needs to cultivate them carefully. Look through the recommendations on an interesting video and save promising ones into the ‘watch later’ playlist (or better yet, separate playlists per topic). Don’t click on random videos, especially from links on social media — use an incognito tab for that.

This works great for me, I have enough videos saved to last me a year or two at least. YouTube learned my taste quite well, especially when it comes to music — found many good albums and tunes in the recs, despite being a snob.