If you want to go even further, use something like this https://chromium.googlesource.com/linux-syscall-support and compile statically.
The syscall interface is stable enough that you can create binaries that will run against Linux kernels from decades ago, if needed.
If you want to go even further than that, you can use APE (αcτµαlly pδrταblε εxεcµταblε) which lets you compile a single binary that can run on Linux, MacOS, Windows, FreeBSD, OpenBSD, and NetBSD.
Cosmopolitan[0] is indeed worth mentioning here. It's an amazing project.