it's true, but it's hard, you only need to click once on a clickbait video out of curiosity and you'll be flooded with garbage until you reset your whole youtube history. I switched to individious/piped and newpipe since for a more quiet youtube experience.
You need to prune your suggestions by clicking the three-dot menu on the suggested item and "Don't recommend video". I started this last year and after a week my suggestions cleaned up and are absolutely relevant and high quality to my interests.
