C and Go are at a very similar level of portability. Statically link your C binary with musl and it will run everywhere the Go binary (built on the same system) would. Neither Go nor C will run outside their architecture or OS, but both can cross compile.

Go makes both processes more user friendly. Statically linking with musl is simple in C (musl-gcc), but cross compiling is a bit of a pain the ass to set up (building your toolchain from the ground up). Not too bad, and if you're messing with building portable executable this kind of knowledge is assumed.