Steam invested heavily in Proton due to competitive threat of a future (consumer) windows where applications can only be installed from the windows store. (and

Steam invested heavily in Proton due to competitive threat of a future (consumer) windows where applications can only be installed from the windows store. (and for their own nascent hardware business) Apple doesn't have any incentive for gaming on macOS. They already make a large amount of gaming revenue from the app store. Gamers on macos would likely buy from steam anyway. And they aren't going to sell many more macs just because the gaming support is a little better.