For me, a handful of things.
- Plasma 6
- Gamescope either by default or as an easily added package
- HDR support
- Faster polling rate for USB
- Whatever it is that makes Wayland NOT have typing lag for me in certain applications. (On Zorin and Tuxedo OS, when typing in Discord and some other things, there's distinct, maddening latency between keypress and results. On Nobara and Bazzite, I didn't experience this.)
- Better removal of orphaned shortcuts & pre-installed software generally. I shouldn't have to track down a .desktop file and delete it by hand for something Zorin installed. Likewise, if Zorin put an application on there, it ought to be removable through the software store or another trivial method. Having to search through ALL installed packages to find and remove the Zorin OS onboarding tour's icon isn't good UX.
Since Aravisian pinged devs, I'll include links with more information on the last point, since it's not merely wishlist stuff:
My issue with orphaned .desktops
Another user's issue with difficult to remove pre-installed packages (this one is universal).