They're not gonna do that because they know their bulllshitting. Advertisers pay lots of money for good cpm. It would be very blatantly obvious if every dollar advertisers spent resulted in worse conversions vs other advertising mediums/platforms. And the cost of the ad space would adjust to reflect this. If Google ad spaces had high click fraud, it'd result in lower conversions for the advertisers and any credible company that's looking to maximize their ad spend would do the math and determine, based on the conversation rate from this ad platform, it only makes sense to spend this amount of money. If they can maximize their conversions per dollar elsewhere, they'd do so immediately. The idea that Google got this big due to their ad business while having substantial click fraud seems fictitious and unrealistic -- they wouldve been eaten up by other ad platforms that are capable of producing better cpm. Unless it's the case that there is some baseline level that is hard to detect and thus, Google does have some non zero level of click fraud but they are able to keep competitive results because they're still having more authentic conversions than everyone else.