This feels at least tangentially relevant :
https://battlechat.co/15-wow-mount-outearned-starcraft-2/
I haven't personally double checked the math behind this claim, but it does broadly track and makes me slightly apprehensive. I don't mean this as an absolute because there are clear and obvious exceptions, like From, but it increasingly feels like the market is actively disinsentivizing devs from making good, unpolluted, games.