Auto-hide the task bar at the bottom, and you've basically got the Gnome UI. Works just fine. It's the permanent screen reservation of the double task bar that really eats up the usable desk space.

Samsung's task bar (when you enable the DeX integration on a tablet) also supports this and it makes for a fine user experience.

Edit: I've enabled "force desktop mode" on my Pixel 9 Pro and hooked it up to my laptop dock. The UI looks almost exactly the same already. Taskbar at the bottom, notification bar at the top.

It's clearly experimental; my ultrawide screen scales horribly, my keyboard app gets horribly confused, and interacting with the top bar triggers a full-screen tablet overlay that looks a bit weird.

However, Chrome opens multiple windows and browses just fine. There are right-click menus, mouse hover interactions, window resizing features (though some apps require the "force resizable activities" flag). Ethernet Just Works, audio/video just works, and I can operate my phone screen while working in dock mode (so apps that absolutely refuse to work can still be operated through the touch screen).