> Except in the real world when we see games offered in multiple places (e.g. Steam and the Epic Game Store) they are usually the same price.
Is that really true? Legitimate Steam keys are sold by stores other than Valve's Steam store, such as Humble Bundle, Green Man Gaming and Fanatical.
I shop at multiple stores that sell Steam keys, and I would say that I only buy less than 1/3rd of my games from Steam directly, due to heavy discounts via bundling and other sales at various online game stores. I find that the alternate "Steam" stores have sales more often than the official Steam store does.
As someone mentioned in another comment, this is the result of yet another monopolistic practice, this time by Steam who requires your game to be priced the same in all stores else it will be removed from Steam.
They'd be cutting themselves out of other stores if they did that. Stores like Steam require that your game is sold at the same price across all stores otherwise it will be removed from Steam.
In other words, any savings from the developer cut is simply kept by the developer, not passed onto the consumer.