Try pulling different codec versions from YouTube? Maybe it got upped to Vimeo or something before?
Also YouTube got rid of some resolution options a couple years back and that kinda adds to the problem of compression-rot of sorts.
> that kinda adds to the problem of compression-rot of sorts
I dunno, when even the 4K version (offered by YouTube) shows the very same compression artifacts on a 4K modern TV, then I kind of feel like you screwed up. At least from the perspective of a viewer, of course from the perspective of the business that saves a lot of money from it.