Working and well-integrated "run this on that rendering GPU", with unused GPUs being switched off (laptop use case).

I want to be able to see true integration between Apps and the WM. I saw a lot of good stuff with the way that Instant Messengers, Downloaders and IRC clients and various accounts could be made part of the normal interface. Now everything is web apps, or worse, Web Desktop Apps, which is also a big huge Electron apps that are more Isolated from each other than ever.

The only things apps share today are notifications, and I could definitely have less of those.

The ability to easily resize scrollbars, KDE.

We had them right for so long.

Trackpad gestures, KDE (like 3 finger swipes customisation). THEM TO STOP MOVING AROUND THE SETTINGS.

Proper HDR support and AMD to put in better HDMI 2.1 support on the open drivers.

Desktop as a service. With the latest feature being worked where apps can be handed off to another compositor, I want the next stage where my compositor and desktop can be swapped with my intervention or notice. Wanna do redundancy? Running the backup live as a hot swap. Wanna do live updates with no interruption? Start the next compositor, try and loads the apps, if nothing breaks, swap the user, if the user doesn't hit the notification to revert kill the last session.

Add in better remote compositor support and it can get really cool. Allowing for a distributed DE across your devices. Making high availability more possible as well, but that might actually be overkill.

Desperately waiting for Gnome Nautilus to not suck major ass (type ahead search, faster performance... hell, just make it like Dolphin, pretty much).

Gnome mobile shell

Cinnamon has this but I wish KDE had it. The ability to right click an application in the task bar and have the option to "move to other monitor."

Not a DE, but I'm really waiting for tearing on sway so I can play games without a second tty 🥲

Sliding Tiling Window Management akin to PaperWM for Gnome.