But it adds a layer of protection, doesn't it? Your known public phone number is one, your verification phone is another one from another carrier. Is that real

But it adds a layer of protection, doesn't it? Your known public phone number is one, your verification phone is another one from another carrier. Is that really an additional layer of protection, or the same layer, slightly obscured? But probably not obscured from the attacker that managed to get your password and just needs the SMS verification code to get into your account.