Isn't app data, photos etc. usually synced with the Google account? Besides, Google claims that the scammers are using social engineering to create a feeling of panic and urgency, so I think the victim would be willing to reset and log in to the accounts again in such a frame of mind.

Some is, some is optional, some isn't.

I'm sure there's a hypothetical scenario where someone successfully runs a scam that way, but there's also a hypothetical scenario where a 24 hour wait doesn't succeed at interrupting the scam.