Existence risk here is HUGE. If GCP doesn't move the needle, Google will shut it down. AWS is a much more living organism and I can't see Amazon shutting it down before their drones take over ...
The scary thing would be if it ends up reducing the rate of innovation because they worry about changing APIs or services too much; obsolete accumulates quickly when you're serving large numbers of people because most business want to write once run till it's dead. But this is true of any service that exposes anything but an extreme abstraction.