The numbers presented in the article (~1 additional frame of latency on Wayland) are from someone using GNOME with the Mutter compositor. This means that neithe

The numbers presented in the article (~1 additional frame of latency on Wayland) are from someone using GNOME with the Mutter compositor. This means that neither the X11 or Wayland session has screen tearing. I imagine the X11 input latency numbers would go down by around half a frame on average if the author was using a different window manager without a compositor.