Agreed.  Going from a 4k monitor back to a 1080P was like WOA!

Works in Firefox.  If I open youtube, zoom in, close the tab, and then open it again, it remembers the zoom I set it to, and it remembers that I haven't zoomed other sites.

Hmm, not really thrilled to try FireFox, but perhaps I’ll try it. 

What in particular puts you off about it?

Syncing auto-fill content. 

I think you can turn that on or off, depending on which is troubling you

tbh I can't really recommend it enough.  It has very extensive and strict privacy options if that's your thing, as well as extensive options for saving and syncing data if you're more a convenience type.  Performance and security is on par with chrome/the best, as shown (in the case of the former) in their own tests where it is faster in some areas and slower in others.  Extension support has always been the best out of any browser imo and that continues to this day with Google and others cracking down on ones they don't like due to conflict of interest (ad company's browser blocking ads, etc.), an issue that Mozilla doesn't have.