This doesn't really sound like a FireFox problem. Not sure how it could be their fault that installing extensions which intentionally disable parts of the brows

This doesn't really sound like a FireFox problem. Not sure how it could be their fault that installing extensions which intentionally disable parts of the browser required to run the websites you use breaks things. Literally none of those websites ever have any problems on any of the computers my family uses FF on, running UBlock Origin.