Now admittedly both Cinnamon and Xfce also depict high CPU usage while rendering in the backgrounds, but Mate takes substantially longer to even show any files, and it keeps having high CPU usage even after the files have finally displayed.
It renders them synchronously. The more artwork we ship the more it struggles. This is upstream and should be reported to MATE under mate-control-center.
Now admittedly both Cinnamon and Xfce also depict high CPU usage while rendering in the backgrounds, but Mate takes substantially longer to even show any files, and it keeps having high CPU usage even after the files have finally displayed.
mate high cpu backgrounds.webm