Apple is now pushing against it. For legal and marketing reasons. The apple arcade model is the opposite of that: no online required, no IAP. I think the loot boxes model is slowly dying in flavor of subscriptions, battle pass and other mecanisms like that.
I can’t speak to the historical component of this, but I suspect that this came about as a natural evolution of in-app purchases. As soon as players could spend money in game, game companies had an additional revenue stream. I doubt we can blame Apple any more than Microsoft or Sony.
Did they purposefully push the loot box model by promoting games that were doing it because they took a cut on every transaction?