Btw @RaveofRavendale's analysis seems to match what I've been seeing too.
I wouldn't be surprised if games on Steam have been making half as much as the previous year starting in 2017 and onward, it certainly seemed true for 2016->2017
So that'd be what, 1/8th of 2016 in 2019?
I think it's also partly devs fault, they put a game 50% off after only 6 months (or worse in a bundle). The games I released past year were discounted 30% max, and I don't plan to go 50% until maybe next Christmas but probably not even then.