It's funny how experiences can be so different (likely by Google's design, of course). I've been having degraded experience with YouTube using uBlock Origin on Vivaldi. I elected to make use of a one-month trial for Premium. Suddenly these problems went away. Interestingly, after canceling the trial, the problems still haven't come back (yet). Things like, I would load a video, it'd start playing, but the browser tab itself would just block for a good 20-30 seconds. The entire time, the video is playing (well, I could hear the audio but the visuals were frozen). Then things would unblock and comments would appear, etc.

The difference between my YouTube interface with and without premium is stark. Aside from the ads, it seemed like the algorithm pushed less slop in front of me to avoid. Purely anecdotal, and likely affected by A/B bullshit (or nowadays would it be more like A/B/C/D/E/F/G/H/I/J/K/L/M/N/O/P/Q/R/S/T/U/V/W/X/Y/Z).