Can you have dozens of different profiles open at the same time in different tabs of the same window?
Yes, I use it at home but also a lot at work. Opening personal account and admin accounts in a bunch of different tabs for a bunch of different sites. Makes it super easy, no need to log in and out throughout the day. I have users that also will have our O365/Okta accounts as well as client O365/Okta accounts. Containers make it a cinch to keep everything separate and logged in at the same time.
It seems that one could also run multiple instances of Chrome or Chromium inside docker containers with X11 forwarding.
I was asking about Chrome profiles, not Firefox containers. I use dozens of Firefox containers already, and it's my understanding that Chrome profiles aren't a good substitute because you can only use one at a time.
No, though I prefer different windows as then you can have different bookmark bars for each context.