I use profiles and containers together in Firefox, which gives more flexibility than either of these features alone.

Firefox lacks a built-in profile switcher menu like the one in Chrome, but the FOSS browser extension called Profile Switcher for Firefox is a similar replacement:

https://addons.mozilla.org/en-CA/firefox/addon/profile-switc...

You'll need to install the connector for the extension to work:

https://github.com/null-dev/firefox-profile-switcher-connect...