As a user of a Firefox-based browser, YouTube's performance really is hit or miss. Sometimes it's ok, other times it's barely useable.
These days I simply queue up videos in mpv. It is much lighter on the resources, and also provides a nice cache that makes seeking through videos a breeze. I can open a link straight in mpv using a very nice system[1]. Once I have an mpv instance open I simply drag links on top of it to enqueue them. (shift+drag if you haven't set the following option in your config: drag-and-drop=append)
It works so well I find myself doing it for other online sources of videos too (e.g. Twitter/X, local TV websites, ...)
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