> Or at least be able to make a single "Linux" binary.

Isn't this what Flatpak/Snap/AppImage try to solve?

Though lately they may not even be necessary. There's a lot less difference between distros now than there used to be in the past. All the majors seemed to have coalesced around the same userland stack, largely thanks to SystemD. If you ship something for Ubuntu LTS, there's a really good chance it'll also work on Fedora, Debian, Arch out of the box.