[charcircuit]

>Can you point to a particualr security feature that would stop functioning and that needs to have an account and that couldn't use a hardware security key for 2FA (if 2FA is a requirement)?

No, as the security key can provide the identity instead of the Microsoft account.

>Helping users use the app store which the majority are capable of should be sufficient

If you want to provide a good user experience you shouldn't stop at sufficient.

>Those users which aren't capable of operating the app store

It's not about a binary yes or no. It's about making it easier to accomplish what users want to do.