[uecker]

This sounds more like random configuration problems with your drivers. The rendering model for modern X clients is the same as for Wayland, so the idea that there could be room for a fundamental improvement is based on misinformation.

[amlib]

Random? I saw it happen on every linux machine running X I came across over the last two decades, it wasn't just mine, it was colleagues machines and so on. Maybe if you combined KDE, AMDGPU drivers, the right distro and X from around 2022 and onwards you could get a mostly smooth experience, but the behavior when pushing the system a little bit or trying high refresh rate would prevail.

The point is, even if you could get a smooth experience it was at best an exception, specially across most of X11 life. There are many reasons why the Steam Deck shipped with Steam running through the gamescope micro compositor, and one of them was sidestepping some of the X11 jank.

[uecker]

Not my experience and we have lot of Linux machines. Drivers and hardware expectations of programs certainly change over time, but this has not much to do with Wayland vs X.