Does anybody buy a phone/car/... based on manufacturer ads? In a sense this is a self-selecting scam. If you don't check 3rd party reviews, then well, you get "advertised"
Yes, and that's exactly why ads are regulated (there are limits to what you claim your product can do), and why there is so much money in ads: they're designed to influence you and make you buy things that you might not otherwise.
Why is the onus on the consumer? Shouldn't the onus be on the business to produce an honest ad?