The biggest misconception game developers generaly have about games is they think they are content like movies/series amd music. That is that the average player plays hundreds of games, one after the other.

Games are successful or failed killer apps. Like any other software mind you. The average player spend 88% of his time / money playing a very few hits like Minecraft.

Which solves your middle-games paradox: those just don't sell anymore. In other words, if you'd make a Commander Keen today, you'd sell 3 copies to your grand-ma (yes grannies play games now).

There is always those who come to tell: I have hundreds of games in my Steam library. "Yes me too". Yes you do and on average you guys still spent 88% of your time / money on a handful of them. They are exceptions of course. There is a line that's somewhere but nowhere near "games are content"