Comment 7 for bug 1937127

Using 'Ubuntu on Xorg' instead of 'Ubuntu' also helps. Because the former having more layers and less internal blocking actually dabbles in triple buffering sometimes by accident. Although I'm not sure if that's the reason it's smoother or just Xorg adds extra GPU load.

Since the default 'Ubuntu' session in 20.04 was Xorg and in 21.04 onward it is Wayland, that would explain a perceived performance drop that some users may notice.