It's not really the same because the reason Valve built out all of this infrastructure was so they could take the middleman's cut. Basically, GameStop buys games cheaper wholesale and resells them at a higher retail price. Valve gets all of that by being the direct retailer to the end consumer.
Not even having to manufacture a physical good is a separate cherry on top of that.
Not even having to manufacture a physical good is a separate cherry on top of that.