I use profiles on Firefox daily and they work fine
https://support.mozilla.org/en-US/kb/profile-manager-create-...
https://support.mozilla.org/en-US/kb/profile-manager-create-...
UPD. The more I look at this, the worse it gets. Hidden under a special URL, requires you to launch the default profile before you can switch to another profile (yes-yes, there are command-line hacks). It's more like a user data manager for devs than profiles for users. Even containers look better than these profiles.
Anyway, your claim was "Firefox has no profiles". That is not true.
If you don't see it in the main menu yet, type `about:config` into the address bar and toggle `browser.profiles.enabled`.