There have been many large fortunes made recently. They prove the point. Facebook/Google are the obvious example.
Companies that are selling stuff for money (spotify, netflix) are bending over backwards to convince investors that this is just pocket money... the real value is in data gathering and monopoly building. Read their prospectus. Netflix's recommendation algorithm narrative was the main focus of their PR for years. There's a reason for this.
Why has Tesla's stock price gone insane? Investors are betting that Tesla's data gathering has given them a meaningful edge in autonomous driving. The market value of this edge is (evidently) more than the market value of all other car companies combined.
Look to tech acquisitions. Why are free apps like snapchat, whatsapp and such worth billions to acquirers like facebook? Have any paid apps even come close to this market value? No, because spyware, adware and monopoly building are far, far more profitable.
Note that I say "profitable" in regards to income and "valuable" in regards to company value. It's true that the economy of buying stuff is big. It just isn't as profitable and therefore not as valuable.
Directing people on what to do could be more valuable than actually selling goods, in aggregate. In particular when their actions have long term ramifications (e.g. politics)
In other ways it could be for insurance or other intangible services that scale well but need to be perceived as somewhat valuable.
Even in cases where you still use goods to capture money, you can price the goods higher through changing buyer’s perception of value. In a way ads can bring you money from thin air if they are effective enough.
I'm not sure it's even possible to discover if profits are concentrated there, the market can look exactly the same either way.
I would challenge this. It's is a technique in the sense that manufacturing cars is Toyota's technique. We would still call them an auto manufacturer and refer to this as a market, at least casually.
Most social media (and also netflix, spotify... so maybe just "media) is feed driven. The anchor to these feeds is data gathering. The data gathering edge (along with network effects) is what makes a $100bn worth $100bn. It's what makes the product work. A twitter feed, e-commerce specials page or targeted advertising widget that is customised well is an entirely different product to an untargeted generic.
If Tesla pulls off self driving, the difference between Tesla (worth $400b on expectation alone) and any other manufacturer their size (probably >$10bn) will be data.
Data may not be the only thing that will be responsible for self driving, but it is proving to be the limiting factor in many of the most commercially important cases.
The OP is all about how revenue of marketing companies shouldn't be larger than the revenue of final goods companies. But there is clearly no such restriction on self driving cars, it's a final product all by itself.
If you mix both into a "data gathering market", you have no means at all to analyze it.
Data is constantly growing new uses, which can go from economically marginal to central very quickly. Data gathering just isn't something that is a distinct market all on its own. The same dataset could feasibly power an ad widget, recommendation playlist or whatever.
That's not to say there aren't giants like Amazon trying to buck the trend...