Another device still tends to be in the same location. I wouldn’t use the own service’s sync but an encrypted backup stored on a separate cloud service should be fine.

Realistically what is the alternative for the average person who does not have two separate physical locations for redundancy? Give your backup codes to a friend?

Not sure what’s the point to them then. If you’re at the mall you’re already inconvenienced

A convenience store next to a supermarket isn’t very convenient unless the supermarket is huge. Most convenience stores tend to be closer to you and stay open more hours than supermarkets. I’m ok paying more for that. Convenience stores here are run by neighborhood people, supermarkets are run by rich businessmen. Starbucks is not that kind of shop though.