I find that even if you get a touch primary device, make sure to get one with a keyboard, Ubuntu, Fedora, doesn't matter, KDE, Gnome doesn't matter, the touch only experience on linux is simply not great. Make extra sure to get the keyboard with it if its optional.
+1 have been trying to make a Linux tablet work. Gnome is alright but it's got a crap CPU and 2gb of ram and nothing lightweight has good touch support annoyingly
I am, very hesitantly, optimistic for the new smithay based compositors. Cosmic doesn't have touch support yet, but it's super light weight, I get better perf then I do even with KDE. I plan on swapping to it full time on my tablet when it gets touch support. (and when some touch friendly gui stuff is available). you also have catacomb which is an actual mobile compositor. Very promising stuff, but still very far out
I was trying things along the lines of hyprland, sway and i3. I have this idea in my head that a touch screen tiling WM would work really well (from what I've seen that's what people love so much about the iPad nowadays anyway)
Hyprland has something called hyprgrass I think which enables touchscreen gestures, still in the process of figuring out how to install that in NixOS though. (it's got a nix.flake but it's not in nixpkgs and I'm still unsure of how to install flakes to a traditional configuration.nix setup)
You could probably look into something like paperwm or Niri, I think scrollable window managers have a lot of potential to be a novel but good touch experience
EDIT: Im not sure if niri support touch, I havent tested it, but I think i might actually try it myself when I get the chance now