A pipe transmits bytes. You can transmit bytes in C datatypes, hence they're equivalent. Whatever serialization is used right now can be reused.

Or even better, actual bools and strings like a real API.

I don't know what the Go library looks like in terms of an API, but the pipes are already requiring serialization. This at least makes that hookup slightly easier, although CGO bridge has some overhead to it, so it wouldn't completely surprise me if a FIFO unix buffer was in fact faster especially if there's serialization in both situations.