Youtube is a mirror, it shows you more of what you watch (at least most of the time.) If you can't resist the temptation of clicking on clickbait/trash, it will show more of that to you.

How to use youtube:

1. Log out, clear your cookies or clear your watch history.

2. Turn off autoplay.

3. Search for a few high quality videos/channels you have seen before, to seed the recommendation algorithm. I use the "Applied Science" channel for this but you use what suits you.

4. Never click on clickbaity trash.