YouTube constantly experiments with the UI (I wish they experimented more with combating AI slop and comment spam). For a while, the playback speed controls got worse, but the current iteration is the best so far.

I’M WONDERING: Is the slider really useful or would it be better to simply have a text field for the factor instead?

@rauschma indeed, much better now!
@rauschma I do use the slider, but not as a slider. It's just an easy way to jump to one of the extremes. If you replaced it with buttons for .25 and 4, and then a text field, I would be just as happy