Noblesse oblige exists because of a moral economy. You can be a horrible Duke, because there's no real reward for being the good one.
This is not that - Steam has to compete on the free market, there is a reward for making the product everyone else refuses to make. In a post-Deck world, it's hard to believe that moral obligation plays a bigger role than the overall hatred of Windows for seamless gaming experiences.
"A complement is a product that you usually buy together with another product. Gas and cars are complements. Computer hardware is a classic complement of computer operating systems. And babysitters are a complement of dinner at fine restaurants."
This is not that - Steam has to compete on the free market, there is a reward for making the product everyone else refuses to make. In a post-Deck world, it's hard to believe that moral obligation plays a bigger role than the overall hatred of Windows for seamless gaming experiences.