Firebase Auth is pretty common and widely used. Any sort of phone number auth, like SMS second factor, requires reCAPTCHA. (And people can complain about how mu

Firebase Auth is pretty common and widely used. Any sort of phone number auth, like SMS second factor, requires reCAPTCHA. (And people can complain about how much SMS 2FA is bad, and I don't really disagree, but it is still pretty much a "lowest common denominator" method and many, many web users can't easily use TOTP or hardware keys). Switching out Firebase Auth is a much, much more difficult deal than just switching out reCAPTCHA.