Why the ad spend isn't working is a critical detail. It's definitely not most money but yes there's a lost of waste because it's a 12 figure industry with lots of politics, perverse incentives, thousands of vendors, and a complex global supply chain.

Fraud is a special case because it's criminal activity and has nothing to do with advertising. It happens in every industry but it's especially easy with online technology spanning multiple countries and data that can be easily faked. Uber was exceedingly oblivious here but I wouldn't extrapolate advertising efficacy from these examples.