Again, you're talking from a moral standpoint, but it's not practical. Who's going to stop Google or other corporations from tracking DMCAs the current way?
> Why does scale matter?
Because of resources. Any defined process needs resources to be implemented; law enforcement is no different.
Google provides services at scale by means of automating the shit of them. The only way to identify legit from fake claims at that level is to also create an automated resolution process, with the results we see.
You may want to limit Google size by forcing them to perform human reviews for all their customer service interactions; but again, how are you going to force them into compliance? You'd need a US judiciary system the size of Google to do it.