On top of what others said, I also like youtube-dl + mpv because it consumes a fraction of the memory Firefox + one YT tab consumes. My main browser is Qutebro

On top of what others said, I also like youtube-dl + mpv because it consumes a fraction of the memory Firefox + one YT tab consumes. My main browser is Qutebrowser where I don't login to Google stuff, for which I use a Firefox profile. So when I'm watching something long like a lecture from any of my playlists, I download it first, quit Firefox, and watch with mpv. If I watch on FF on a large screen the computer starts swapping and I have to go kill some apps.