This is only true with Google as far as I know. And I'm fairly sure that all cloud providers only have maybe 10 edge routers in the US so the utility is limited

This is only true with Google as far as I know. And I'm fairly sure that all cloud providers only have maybe 10 edge routers in the US so the utility is limited. You can't have too many edge routers because they rely on IP Anycast which is dangerous to do if your routes are too similar.