Just because you can use it from C doesn't mean it's a C ABI. You can do almost anything from C, but the semantics of the APIs require additional work in order to use correctly. Just because golang can interface with C doesn't mean C APIs have a golang ABI right?

Which of the platforms (other than Android) require you to do extra work to talk to the underlying system API with a C ABI?

iOS certainly doesn’t require any extra work, and even exposes several C api for frameworks as well (not even including ObjC).

And even in the case of Android, the system provides JNI facilities so it’s not foreign to the system.