Earlier quoted context omitted.
Desktop Linux has all of that compatibility. Nothing fundamental has changed: You need the libraries, and if you have them, it works, just like in Windows.
No, not really. You can get chroots to run on a command kernel but ABI changes happen without soversion bumps which stupidly complicate matters. Godhelp you if your application tries to use weird ALSA or even worse, OSS features. I've been down that road, there's nothing good to say about it.
I have plenty of experience which says otherwise, both for Windows breaking compatibility and Linux keeping it.