Bit OT: I’m interested in an open standard for “push” 2FA. Receive a push notification on Google or Apple’s standard platform, or at the least be able to open t

Bit OT: I’m interested in an open standard for “push” 2FA. Receive a push notification on Google or Apple’s standard platform, or at the least be able to open the app and just tap the account to send second factor auth (maybe when you open the app it queries all accounts to find which is currently waiting for auth). Are there security concerns blocking this?