These latency numbers all look terrible to me tbh. I got better latency numbers (a little over 2 frames in KWrite, close to the theoretical minimum with X11 compositing) with an AMD GPU w/ open drivers, KWin, X11 and compositing enabled a couple of years ago. Measured with high fps recording on a phone camera filming keyboard and screen. Both Wayland and KWin changes should have improved the situation since then. I suspect the games, the screen and / or the graphics drivers which are presumably "review optimized" for frame rate over latency.

Actionable advice from the article: Using Wayland natively from Wine does seem to help, especially against latency jitter / for consistent frame pacing, which is a typical improvement for Wayland.