> Firefox added profile switching recently.

I think this was as recent as 25 years ago?

Recently they added some new UI. There was and still is (I think) classic Profile Manager UI, which you can launch with

  ./firefox -ProfileManager

or access UI in about:profiles.

But you don't have to use any of those anyway - see my comment above (a response to parent).

They actually have at least 3 kinds of profile: 1. containers - As they say its somekind of sandbox, technically a profile 2. profiles that are accesible through about:proflies, which they had for years, and probably the one you are talking about... 3. New profiles that comes with a pop-up much like how chromium browsers shows it

The old UI was pretty difficult to use, and hard to discover unless you knew where to look though.

What about the old UI is difficult to use? I am assuming you are talking about the profile manager.

Odd - they've had that for years, but only on the command line. Wonder if it's different under the hood? They also have firefox containers which also never quite became a first-class feature (you have to install a plugin).

>Works good.

does it? same binary, same machine, same display, same 781 other heuristics.