I think sometimes people tend to ignore 2 facts:
- a profitable business can exist with games that don't make as much as 2 million USD a day, and there are lots of them, just go to the top free charts and probably many of these apps might not be heavy in in-app content but they have ads and they are often overlooked.
- because people like games and know how to make them they often ignore some of the most important keys for a commercially succesful product: polished graphics, good UI/UX, marketing, UA... this might take time to realise but it's very easy to differentiate an "amateur bad" app on the store than a "appealing one"
With all this I mean, there's people making good money but chances are that they don't show themselves in forums or share info about money, If I recall correctly the mobile gaming industry will be worth 160B in 2020!