Enhancer for YouTuber is intuitive and highly customizable. I use it to:
- set the default playback speed to 1.5
- adjust playback speed via a toolbar which only appears when I hover over it
- automatically pin the video to the bottom right (like PiP mode) when I scroll down to read the comments
- dark mode

I've been using Enhancer for YouTube since a couple of years ago and I can say this is one of the best and more practical extensions I have used.
It makes using YouTube much easier and doesn't interfere with your browsing.
I simply love it.

the best and has lots of features really useful

recently the miniplayer still appears despite being turned off

The ad blocking feature is wonderful. Before I used this so much time was wasted on annoying ads.