With Google Authenticator, there is no notification, is there? As a user, you have to open your phone, open the app, then scroll to the right code, and copy/paste it. (The lack of search in one of the reasons that made me switch to Aegis)
I always thought Okta was kind of weird, because it's just a notification that says "allow/deny" and it's easy to click the wrong one.
It's possible I'm confused by GP, but there's two things being discussed here I think:
First, Google Authenticator, which is in fact just totp which can be used for both Google 1p and any 3p TOTP thing. And second Google's push-notification based auth checks which are used for only certain 1P Google apps (like logging into your gmail or youtube).
I always thought Okta was kind of weird, because it's just a notification that says "allow/deny" and it's easy to click the wrong one.