It somehow happens that OpenBSD feels like an whole operating system rather than Linux distro built from various components. For example, when pledge(2) and unveil(2) appeared, many user-space programms got patched as soon as possible. You can see simillar process now, after pinsyscall(2) appeared and syscall(2) was removed.

I heard, that there is something simillar in FreeBSD with zstd compression.

For me cons is that you can't run some programms that depends on Linux kernel insides, like rr debugger, which depends on some specific of linux ptrace(2): https://github.com/rr-debugger/rr?tab=readme-ov-file#system-...