What does latency have to do with 2D? Are you suggesting UI toolkits are writing GPU commands synchronously? You should fill display list, fire it and forget about GPU until the next update.
I expect a screen that supports or is designed for pen drawing to be somewhat more likely to be above 60Hz. All of these things are niche things that not many care about, but in any case, it’d be nice to be able to do better. And like with Formula 1 race cars, benefits from high-end techniques tend to trickle down to other more mainstream targets in time.
Bottleneck is in the input layer. While using a desktop computer look at the mouse cursor, now move the mouse - hardware accelerated 2D graphics, imperceptible latency.
Low latency thru orthogonal multiplexing https://www.youtube.com/watch?v=t1VcC9_yhc0