It should be possible to reduce the latency quite a bit if a Wayland compositor had that goal in mind. It's something we're working on for Sway. Sometimes you have to choose beween (1) render correctly and (2) respond immediately to user feedback. When resizing windows for example, we can scale the old buffer up (stretching it) while we wait for a new buffer from the client, or we can wait to give you that feedback until the client has prepared a new buffer at the right size.
