That's great, I wasn't aware that mpv was portable to Windows. Writting the above I vaguely realised that the video player example didn't have many legs to stand on. I used it because, for me, the interoperability of mpv and ytdl is a poster child for taking content that's on a closed platform (Youtube) and lifting it out for high interoperability with the rest of the system.
It's a fair point that Windows doesn't put burden on applications to be less interoperable, but it doesn't facilitate it either. The UNIX philosophy has completely bypassed Windows. You can do things on its command-line, especially if you augment it in various ways, but do you ever feel like it's a first-class citizen on Windows, or its ecosystem? I'd argue there's reasons for why, as a rule of thumb, only the biggest FOSS projects are compatible with Windows.
It's a fair point that Windows doesn't put burden on applications to be less interoperable, but it doesn't facilitate it either. The UNIX philosophy has completely bypassed Windows. You can do things on its command-line, especially if you augment it in various ways, but do you ever feel like it's a first-class citizen on Windows, or its ecosystem? I'd argue there's reasons for why, as a rule of thumb, only the biggest FOSS projects are compatible with Windows.