As someone who used to operate a domain parking service, I've seen evidence numerous times of google taking away publisher earnings because of alleged clickfraud, but then not refunding advertisers for those same clicks.
I know of three advertisers who were appearing in AdSense ads on a publisher page back in 2009 that Google refused to pay out because of "click fraud", and none of these advertisers received refunds or any indication that they were defrauded. Google took the money that was supposed to go to the publisher, kept it, and didn't refund the advertisers. They probably never do. I ended up paying $800 out of my pocket to compensate my users for the lost revenue.
I have also worked with hundreds of advertisers in the SEO space, and I have never, ever, seen someone say they had ad money refunded because of click fraud, yet I've seen plenty of publisher earnings held back because of supposed click fraud. Google's fight against click fraud is really just a fight against paying out to publishers, full stop.
Google also used to do this crazy shit (don't know if they still do as I'm not in that space anymore) where they would change the TOS at midnight and then retroactively block the past month's earnings on hundreds of accounts that are violating the seconds-old TOS. Pretty sure that is illegal as well.
If you think about it, Google has zero incentive to stop real click-fraud, especially if their chosen course of action is to just keep the money and not have to pay publishers or refund advertisers. This space needs regulation, and it's needed it for over a decade.
I will happily forward what I have if someone knows how to get in touch with investigators.