Uber discovered they’d been defrauded out of 2/3 of their ad spend
The Uber incident has been known for almost a year.  There are other instances, mostly undisclosed audits which have shown similar results.  One audit revealed $220m in ad spend for a global brand with a +$500m budget had no impact on their results, it was vapor.  On the finding of these results, they didn't want public embarrassment or the hit to their share price.Not everyone in the industry is fraud, not everyone in the industry is a huckster.  But most of the industry is people talking up their game and creating a facade, from Brand CMOs to Pubs gaming their performance numbers.  Fraud can be reduced, but few want to engage in the rigor and even less want to recognize actual/validated performance when the current fiction suits their purposes more easily.