[smoldesu]

Sure, as someone who actually really likes x11 I think the distinction is easy to make. x11 is a feature-complete display protocol that has lots of bells and whistles; it's great for people who want an old-school desktop experience, but there are a lot of anachronisms that make it difficult to support for modern devices. For one, the compositor situation is a mess which makes it really difficult (if not impossible) to lock yourself at a smooth refresh rate. For two, the overlapping window model built into x11 display servers doesn't really reflect the fullscreen-app paradigm that most people expect from a smartphone. Finally, gesture support is a wreck on x11 unfortunately and held back by a number of issues (not the least of which being horrible stutter). There's a reason the community waited until Wayland to start building Linux phone stuff.

I say this as someone who likes Xorg more than most people. x11 is great if your workload can take advantage of it's feature-completeness. Most users would happily trade in VNC support for a locked 60fps interface and gesture support though.