Isolation of trackers, always a good thing! Would be 5* if it were possible to manage the stored data for a particular group of containers, Shopping, News, Google, etc.
A news site that downloads 50 or more, highly intrusive and persistent cookies and trackers will need "cleaning" far more than my "Work" tabs that are typically Linux and FOSS technology which (in the main) seem to use minimal cookies.

Good and perfect for privacy. It would be good if this were ported to Android and iOS devices

What a big disappointment. I was excited to try this out since I actually had a problem this add-on had the potential to solve: I typically use the 'Firefox Home (Default)' setting for new tabs. When I add a new tab when presenting my desktop in Teams during remote work, the tab would show icons for websites related to my personal browsing. I expected this add-on to segregate history (which, I believe, the icons depend on) by container instead of just cookies. No, it doesn't. What is the point of not 'contain'ing the history?

nice, very helpful, thank you

Great Add-on. I use it every single day to keep web sites in their own containers!! Great work folks!!

"You need an updated version of Firefox" Are you kidding me?? As of 17 December 2021, Firefox 91.4.1esr *is* the latest Firefox version in the ESR branch.

Don't you know your own software, Mozilla?