Functionality is similar, but containers are a lot easier to manage than profiles in FF for me. Everything is right in the container icon and you don't have to re-login like when setting up profiles. You can create new containers and remove unused ones in a couple of seconds vs profiles which are much slower to manage.

I don't bother with profiles any more, especially since there's a one click option to open all the container tabs in a new window as well.

The huge downside with them is they don't sync across devices. If/When this comes they will be perfect.