Earlier quoted context omitted.
Google's services are not free. You trade your data, screen real estate, and attention for their service. This is worth a lot - Google is worth a lot. They didn't do it by giving out services for free.
I know what you are saying, but actually this service is free. Blocking bots effectively is in both the website owner and Google's interests, because bots disrupt the value propositions of both. And you could argue that it is in the website reader's interests too, by extension. Given their scale and resources, Google are able to provide a far more effective bot detector than any of us could do on our own. I for one a…
You may argue that the trade is in the website reader's best interest. This is a different argument than whether it is free.