But then bad guy just logs in to Authy with the same stolen credentials because most normal people will probably use the same credentials for everything, includ

But then bad guy just logs in to Authy with the same stolen credentials because most normal people will probably use the same credentials for everything, including Authy. And arguably, the smartest tech-savvy folk wouldn't be storing their 2FA keys in the cloud like Authy anyway. If your cloud account is protected by 2FA that's also in the cloud... it's turtles all the way down.