It is a coincidence. The issue is commands in the game clashing with the browser, an environment it was never meant to run in. Whatever command-key you want to use for shortcuts, both applications have equal claim to wanting to use them - is is about application shortcust vs. application shortcust not OS shortcuts vs. application shortcuts. It only works out because the game was developed for a different platform than the browser, which by coincidence uses a different key for commands.
It is a sort of coincidence that Apple decided the pinky finger button should be control rather than command. The other way around and crouch-jumping would be more difficult and you'd want to rebind it... but you would then run into the same keybind overlap issue as experienced on Windows/Linux.
What’s insane about a standardized key mapping that is predictable across apps and works? On windows you can never be sure what any key combo will do from app to app.
I mean it's an intentional design decision to avoid using ctrl for OS shortcuts. Coincidence is a bit much! (Not an Apple partisan, stopped using Macs when I couldn't open iTunes without being pitched Apple Music)
The control key was designed with the intent of subtracting 0x60 (or 0x40 if you assume the base state is caps) from a character code to send a control code. It's not some coincidence that "ctrl-c" sends an interrupt on the console, if you take a look at any ascii table[1] you can see it was designed that way.
Repurposing that key to instead perform unrelated arbitrary commands is the insane move, and it only seems normal because you grew up using Windows and never thought to question it.
Apple's mappings make much more sense, especially with both OSs having a Meta key.
But I still won't get them any credit, since it is purely a coincidence that their mappings happened not to mess with this one browser game.