Calling something Linux is very specific, and it's just not true for macOS. E g. if someone brings you an encrypted drive that uses LUKS, you can't mount it in macOS. But both are Unix-like, macOS even being UNIX certified. However, from what I understand, these mostly concern a specific part of the stack that doesn't guarantee that you can work with the other system, this is rather something for applications to target. I mean cool I can enter a shell and list files on macOS, but that doesn't fix the problem.