> > OpenBSD allows making syscalls from static binaries as well.
> Do you have a source for this?
One article from 2019 about this can be found at https://lwn.net/Articles/806776/ (later updates https://lwn.net/Articles/949078/ and https://lwn.net/Articles/959562/). Yes, it does not have a stable system call ABI, but as long as your program was statically compiled with the libc from the same OpenBSD release, AFAIK it should work.
Yeah. Do you have any information as to how/when the OpenBSD system call ABI has changed recently? I wouldn't expect that to happen very often.
I upvoted for the great links, but I still don't think a static binary that will break in the future is meeting the expectations many have when static linking.