I think Google is trying to solve the problem at the wrong level - people do not really understand their computing devices enough to understand the risks, they never had to learn or were taught how to use such devices, they were only told it's easy and to not ask questions. The interfaces are designed in a way that allows them to get by with almost no understanding of anything. Which is why such solutions may also be bypassed by a determined attacker. Such scams only really expose this fact. So there is no good way to differentiate between the two groups.

My solution is educating about smartphones and computers first. Not in an in-depth way, but people need to understand what "application", "verified" means and what are the risks. I think android cleaned up the abstraction enough to make this possible.

Being able to tell if an app came from a trusted company or not is a good thing, but I would rather such a solution be managed in an OS-independent way, not controlled by Google. Applications not authenticated by a company should not be second-tier citizens, but there should be a clear warning (and the users should already know the difference before even seeing this warning).

I think the scams and phishing also expose another important problem that nobody tried to tackle yet - you can't authenticate calls, sms messages or emails. There is no good way of telling if it's actually your bank calling you, or if it's just a scammer.

In the end, we also need to accept that not all scams can be prevented, at some point if someone is calling as a friend of your family member, and is asking to urgently transfer money to an unknown account, and you fall for this... I really can't think of a technological measure that would've helped, it's only you and your common sense.