You can do similar with some games on Mac but it’s done through the windows client which is what I assume is being measured - couple that with the comparative difficulty of setting wine+steam up and you have negligible mac usage.
Which difficulties are involved in selecting a Proton version from a dropdown and clicking install?
I only boot windows to play VR. Gaming on linux is easy* compared to the early days. Nobody messes around manually with wine instances anymore, dude; wine/protontricks is a thing. (98% of the time at least).
[*] Easy for the games that run on Proton, which according to ProtonDB is ~70% of the titles on steam (those with silver+ rating).
Edit: I should mention, I swore off AAA gaming years ago, so that likely contributes to my satisfaction with linux gaming. Really, though, nothing of value was lost to me.
That it doesn't exist on macOS?
The point I was making is that the overwhelming number of games on steam are windows only games, the valve semi-supports on linux via proton, which they do not offer on macOS. The net result is anyone jumping through hoops on macOS to use steam+wine is recorded as a windows user, even if there were even remotely meaningful number of such users.
Hence linux steam users matching macOS steam users is an obviously plausible outcome.
Hoping to see more movement on Mac compatibility in the future, but even with the recent game porting tools, I won't be holding my breath. It's sad, these laptops seem like they'd be decent for casual gaming (One of my main computers is a MBP. I use all the OSes.)