Oh gosh, please understand that none of this is new to anyone who works in the industry.
Everyone knows how fuzzy it is. Everyone knows the scheming from the VP Marketing, to the Agencies, to the Exchanges etc..
But we also know when it works, and when it works well. The more experienced marketers have an intuition for how all the various different marketing activities combine to form a synergy. And how it gets disproportionaly harder to do in a low cost way, to the extent that large, fat, profits exist that can be extracted.
But that's no different than any other part of a company. P&G could drop 1/2 of their White Collar workers and probably figure out how to get along just as well. Union workers in Auto Plants have benefits that put them way ahead of what they'd have otherwise, but they have the power to extract it. Governments pay out to 'no bid contracts' - and especially lawyers - considerably more than they have to.
Every sector of every industry is making sausage, the issue is to highlight the actually illegal stuff, and put some legal parameters around it.
Google bidding on it's own auctions is a problem.
Google's control over adjacent parts of the value chain is a problem.
Google's metrics, if they were fabricated, that's a problem.
But bad marketers that spend too much on ineffective campaigns, that's not a legal problem.