It doesn’t solve all the issues you mention, but YouTube Search Fixer [1] [2] is a browser extension that at least lets you remove irrelevant results, Shorts, live streams, and more from search. It makes results a bit more usable.
Disclaimer: I’m not affiliated with YouTube Search Fixer. I’m currently working on https://maxxmod.com, a YouTube-focused browser extension that will include search improvements, so I’ve researched the ecosystem.
Just read the description and OMG soo much crap, thank you so much for this. I guess when I filter these dopamine leeches in my mind I kind of lump them together