Is there a real reason to keep the “Unity look” in the default Ubuntu, other than just the look?
The top panel in Unity had a job to do, holding app menus, the global menu, while the gnome-shell’s top panel is just taking space, giving nothing much, especially useless on small laptop screens. Most important, gnome apps don’t carry any app menu top panel.
The Ubuntu dock, a fork of Dash to Dock, only configures the Gnome shell’s Dash, which doesn’t have much possibilities. It cannot minimise, maximise from the dock. It cannot hold a clock. It cannot hold notifications and so on.
On the other hand, the Dash to Panel had placed the gnome shell’s dash in the top panel. The D2P can be placed now in the all four sides of the screen. Everything on one panel/dock, the minimise, maximise is available and so on. If D2P is chosen for default Ubuntu, then only one external extension has to be maintained. Actually, doesn’t have to be maintained, except to change view-app-grid-symbolic.svg to an ubuntu logo icon. Then, the only other extension to maintain would be the desktop-icons. So, less trouble.
After all, most of the users would immediately install D2P, even though Ubuntu “hides” the chrome-gnome-shell, synaptic and so on, users do read the 'net.
Then, there’d be Ubuntu remixes coming out with D2P and the popular Manjaro would also replace D2D for D2P, now that D2P can be placed on the left side.