Exactly that. A local only path that provides high performance.
Remember the original comment was the claim that Xorg could easily do remote windows years ago. This is only true using the low performance path that modern operating systems have universally rejected.
No, the original comment is that by writing an Xorg compositor I could project separate windows into separate surfaces at arbitrary positions in the 3D world. There's no need for network transparency and you can very well do with an HDMI cable (actually, I was using an HDMI cable -- this was 10 years ago).
Network transparency is exactly what people want. If you're going to say just tether it to your computer with a wire then you just aren't understanding the product.
