It is not enough to provide portable machine code to make games portable, there are lot of different APIs that games need: graphics API, windows API, input API,

It is not enough to provide portable machine code to make games portable, there are lot of different APIs that games need: graphics API, windows API, input API, sound API, disk API and so on. Sometimes they need kernel modules for anti-cheat and anti-piracy features. What saddens me is that open-source OSes do not want to provide a common set of APIs so that the developer only has to write and test the code once and it works everywhere. There is flatpak, but as I understand, it doesn't provide a set of APIs, it simply packs a Linux distribution into a virtual machine without any specifications or documentation. So ugly, and no compatibility for smaller non-Linux OSes.