No you are not missing anything in my opinion. The reason this is not offered (IMHO) is that a lot the use (on the users side) of 2FA is from people that want

No you are not missing anything in my opinion. The reason this is not offered (IMHO) is that a lot the use (on the users side) of 2FA is from people that want better security, while a lot of the push (on the developer side) for 2FA is from people that would like to see the use of passwords almost disappear.