C++ developers don't make their own event loop. They use epoll which is provided by the kernel. That is still the area the C/C++ ( and Rust ) have over Go, they

C++ developers don't make their own event loop. They use epoll which is provided by the kernel. That is still the area the C/C++ ( and Rust ) have over Go, they can use syscalls without requiring the goodwill of one of the language developers.