And if you don't know about this, it's difficult to find out what's the problem.

You can do debugging it’s just insanely slow right?

Not really, iOS does network magic over the wire.... back in the jailbroken days you could launch a daemon on the phone and it paired with a local app via WiFi to allow wireless debugging.... they did what apple does and rolled that feature in later on.

It really does not. Set the right flags, and your debugger traffic gets routed into the tunnel.