Most other companies would still nickel and dime the adults, though.

They still do that, Valve popularized the concepts of battle passes (with Dota 2) and loot boxes (with Team Fortress 2). They also took a paid game with TF2 and added all that monetization after the fact.

Counter-Strike especially has a pretty nasty gambling scene that Valve refuses to control, even though its only possible because of their marketplace and APIs.