`about:profiles` shows you a window for creating and switching to a different one. I add that as a bookmark on the bookmarks toolbar of the two profiles I use
I believe there is a `-P` option to open a new window with a specific profile. I do not use it. I usually just open the browser and then go to the aforementioned bookmark and open the other profile.
I use different colorways to differentiate the windows between the two profiles.
There may be addons that alleviate a few of the pain-points with Firefox profiles. I have not tried to find any.
I mostly use containers for everyday work, but when a site looks borked (which typically happens because of strict ad-blocking extensions doing their job), I temporarily switch to my "unprotected" profile that has no ad-blocking whatsoever.
(And also when I test new extensions I build, but that's a very niche use case.)
Chrome doesn’t. Safari has something similar.
For my money this should be the default behaviour on ff.