But they sell retro games too! Yeah, that little shelf in the middle beside the shirts. No, the really skinny one. The one with one obscure GameCube game, 2 OG Xbox games, and a bunch of crappy Disney Channel DS games. Yeah, that’s the one. They sell retro games!
It’s a little easier when the machine is dedicated to that and only that. The OS doesn’t have all this extra crap running in the background that takes resources from the game because it was designed for that in mind.
That and devs have just one machine to design their game for versus trying to make their game run on hundreds of machines with very different specs.
Some devs, especially first party devs who work closely with or directly for the manufacturer also have insider knowledge of the system they’re developing the game for. The Crash developers did this in the PlayStation 1 era by tapping into resources that other games weren’t using to push out even more performance from the hardware.