Firefox also has Multi-Account Containers add-on which is much more lightweight ...

Hello71 · on Sept 9, 2018

Ah, yes, I forgot to mention that. This is basically Firefox learning from Chrome's mistakes after 10 years, just as Chrome learned from Netscape's mistakes. Chrome added in-browser support to profiles, then Firefox added preference and add-on sharing.

Flimm · on Sept 9, 2018

I don't quite understand your comment. I think you are assuming that Firefox's containers are like Chrome's profiles, but they're not.