I use Edge at $JOB (because we live in Windows land and Edge integrates better with Windows stuff) and Firefox at home. I also used Chrome in the past.
Whereas I agree Firefox used to be way better than IE when I first used it, I can't really perceive any notable difference on performance for those 3 browsers.
There are some minor diffs (edge has veritcal tabs and allows login in with your AD account), but that's it.
More important in this day and age is since Firefox 91 there is a checkbox in privacy and security to automagically SSO using the account on the Windows 10/11 Account Settings page that Edge uses.
Whereas I agree Firefox used to be way better than IE when I first used it, I can't really perceive any notable difference on performance for those 3 browsers.
There are some minor diffs (edge has veritcal tabs and allows login in with your AD account), but that's it.