There are exceptions. I think Google search ad works so well it’s eating the product. I think YouTube’s TrueView is great for modern brand advertisers (safety issues aside). But by and large, banner ads, forced video pre-rolls, etc don’t work. The negative message of the format offsets any message you try to convey.
Yes, fraud is a part of this. But I think a lot of this evidence looks the same as if none of their targeted, performance-based advertising was doing anything at all, beside really weak branding.
Genuinely interested to hear from people who disagree.