The only reason Google think we do is because they implemented AdSense incorrectly. E.g. Using an impractical and underpriced PPC model. If they used a fixed pricing model this would not be a problem, and fake clicks would not even be an issue.
The site claims they get 1M visitors per day; should an advertiser believe them?
I am reminded of a story of a retailer who adódnak l accidently stopped advertising online and so no adverse change in sales. While I can't find the exact one I have in mind, it seems this isn't rare.
https://www.forbes.com/sites/augustinefou/2021/01/02/when-bi...
On the other hand, most of the money in advertising today is in brand advertising. No one clicks through an ad for Ford or Coke and buys immediately. You can run experiments on these at a very coarse level, but that level is approximately "the English speaking internet". Which means brand advertisers are willing to pay far more if they know real people are seeing their ads.
(I used to work in ads, but quit a year ago and have no plans to go back)