Yep. It's encoding a video stream, transmitting it, decoding it, capturing input, sending input back if any received, repeat. It's not a direct display stream; It's essentially video streaming to the device, similar to concepts like GeForce Now or Steam Link. This time implemented on an OS level, but still no different in concept.
Plus, most Macs wouldn't be able to play most games at those super high frame rates anyhow.