Will Firefox go extinct like Netscape did?
THIS. The first damn thing I do on a new PC/VM. I work with multiple clients, they each have their corporate SSO stuff and its so damn convenient to keep them all in their own containers. Same with Google stuff, containers are so much more consistent to switch between Google accounts than their own switching thingy (just try switching between accounts in AdWords).
I’m pretty sure Brave profiles are the equivalent or at least an analogue.