Backward-compatibility 1: Linux is not good at it

[sorcerer_see]

Due to the de-centralized and fragmented nature of UNIX-like OSes: OpenBSD, FreeBSD, Haiku (BeOS), Slackware, RHEL, openSUSE, Debian, Ubuntu, archlinux, etc, etc, these could and can not manage to adhere to universal API's and other standards, like centralized controlled OSes like for example: DOS, Windows, macOS, CAN.  In Unix-like OSes API's and dependencies continuously change between different kernel releases. Linux distro's do aim at current kernel cross distro compatibility within their own major Linux family like: Slackware, RHEL/Fedora/openSUSE or Debian, but this compatibility does not extend backward to older kernels. Linux distro's and software in repositories are submitted to a continuous regular update cycle which causes unmaintained applications to lose compatibility very fast, like around 1 year at max (with exceptions existing).

In Windows one can often run, for example, a application created for Win95 on, let's say, Windows 7, which gives like a 15 year or more backward compatibility. Windows 11, however, is a different story, which dropped 32-bit support(!).