The article links to https://support.mozilla.org/en-US/kb/profile-management. From my memory of how profiles worked previously it's mostly a fresh coat of paint for things you could do before.

The two most exciting things to me:

1. You can now launch and manage profiles from a menu hidden in the account menu (feels like the wrong place to put it, but shows up for me even though I'm not signed in)

2. Mozilla actually cares about profiles again. The feature felt mostly abandoned before, nearly inaccessible without command line flags or the very bare-bones and ugly about:profiles

Still difficult to tell for me. I enabled `browser.profiles.enabled` and now there's Profiles in the hamburger menu. However, it only shows a default profile. It does not show any other existing profiles.

Yeah, that is exactly the problem.

So far I see that it is easier to create/open/swap between different profiles (before the easiest way was literally the terminal). There is a small icon next to firefox dock icon on macos for each profile that you can choose, which I do not remember before. So you can easily distinguish which icon corresponds to which profile window. And that you can edit the theme for each profile easier.