Google shouldn't really have to do this. Replace GoogleBot with BingBot or GCE with AWS and you still have the same problem. A website operator should be working to make sure search crawlers don't consume too many resources given that the bots follow rules.

Otherwise you'd have a team at every cloud provider trying to figure out how to manage bots.

Now you're suggesting that Google basically devotes a team to detecting "crawler-free-quota abuse", when the real solution needs to handles crawlers from many different sources that aren't all Google.