Comment by VileSquirrel

You can mostly do it with ublock origin filters. Here are mine, though they do more.

www.youtube.com###contents-container > .ytd-rich-shelf-renderer.style-scope

www.youtube.com###rich-shelf-header

www.youtube.com###content > .ytd-rich-section-renderer.style-scope

||www.youtube.com/shorts/$document

Alternatively on firefox you can use either the "unhook" extension (https://addons.mozilla.org/en-US/firefox/addon/youtube-recom...) or "enhancer for youtube" (https://addons.mozilla.org/en-US/firefox/addon/enhancer-for-...) extension (which has an option for this).