[fhrow4484]

Never used command line for profiles, I'd just go type "about:profiles" > "Launch profile in new browser".

This opens a new window with that profile, but you can switch between each window at will.

The lack of discoverability of that "about:profiles" page is indeed a UX issue compared to chrome, but other that that it works pretty well.

For most use cases, I find the more lightweight multi-account-containers more useful though.