This is the wrong assumption to make. I can tell you as someone with a powerful rig that is by no stretch a "slouch" sitting at 0% CPU and 0% GPU I have seen Youtube act like garbage for absolutely no reason. I've even had video playback skip ahead a second as well and it throws me off when watching videos.
> Get a faster computer
or... and keep up with me here. Google has been known to do A/B testing on users. Just because your part of "B" group that doesn't see it doesn't mean that it's not happening. It only means Google is artificially putting their thumb on the scale and I take serious issue with people handwaving issues with "get a better computer" Nothing is wrong with my computer and only Youtube has this issue, any other video platform does not do this so why is it only Youtube?