And as soon as all of the major players are using the same algorithmic system to set their prices, they are effectively a cartel and any prospect of real competition disappears. It's exactly the same situation we're seeing with RealPage in the real estate industry.

And if anyone objects or raises any claim they'll just shrug and say it's those darn algorithms again.

If this theory were correct, why are margins on flying sub-5%?

This kind of collusion works very well for supply-constrained apartment rentals with high switching costs, but works less well for commodities.