This is true, but unfortunately, a lot of games are almost completely unmaintained, especially on macOS. Many of the smallest indie game developers don't even own Macs—they either borrow their friends' machines to do one-off builds, or they use cross-compilers and rely on fans for testing.
Even just recompiling the game might be a challenge for a lot of developers in the "long tail" of the Mac game library.
This is my sentiment as well. A twitter summed it up nicely:
> the notion that every developer of every app is part of the constant, incessant update loop that Apple encourages is fundamental to the problem. Someone's super personal narrative unity game from 2013 is not getting updated!
Even just recompiling the game might be a challenge for a lot of developers in the "long tail" of the Mac game library.