You can't revoke them if the paper is in the wrong hands, and you don't have a normal access to your account. (Well, they are much like a password in this regard.)
It's just different risk profiles. Your biggest risk might be to drop your phone and lose all the 2FAs in a Google Auth app. Or your biggest risk might be losing your wallet to a thief or robber who is going to hijack your accounts.
I think the chances of the kind of person who steals your wallet also being able to leverage pilfered two-factor authentication codes to hijack your accounts is almost zero.
