Mostly A. Why bother with ever getting a password and having to deal with it in any way, versus delegating that aspect of security to a FAANG-level company with

Mostly A. Why bother with ever getting a password and having to deal with it in any way, versus delegating that aspect of security to a FAANG-level company with a > $1m security budget? You can store your password yourself, sure, but how certain are you that you're doing it "right" and that "right" today will be good enough tomorrow? 15 years ago MD5 wasn't perfect, but it was good enough versus the other common/stupid methods of storing the password directly or storing it encrypted vs hashed. How certain are you that Argon2 is going to stand the test of time for another couple decades?