[chatmasta]

How so? I use Firefox for all leisure activities, including extensive YouTube usage, and have never noticed any issue. I’m running uBlock Origin and Sponsor Block. I’m logged into a dedicated Google account I made solely for browsing YouTube (so I can keep the viewing history without linking it too obviously to my main Google account).

[ricardobeat]

Page load takes twice as long as Chrome, videos buffer more slowly, and memory usage grows much faster. After a dozen tabs it starts visibly lagging when you press play/pause, the exact same session works flawlessly in Chrome.

It doesn't seem to affect everyone equally. Pretending to be Chrome sometimes helps - not too long ago someone found a piece of code that introduced seconds of busy delay for any non-Chrome user agent.