[tracker1]

If the OS (not an app) could allow you to tweak the native pixel resolution, scale, size of each display, even under "advanced settings" that would go a long way towards helping.

This is at the Operating System level, not like some random one-off application.

For me, the one feature I miss the most is a checkbox option for "Native Scrolling"; Did this really need to be removed?

[kps]

X11 did — run xdpyinfo and you'll see its idea of screen dimensions and resolution. (It's unlikely they'll have been configured correctly, of course.) If you look hard enough, you can find some ‘outdated’ plain-X software from the workstation era that respects it. It was the ‘Linux desktop’ crowd that threw that away, since they couldn't think beyond building Windows clones for PC clones.

And the vector-based competition to X (e.g. NeWS, Display Postscript) would have done better.