Reassess in a couple of years when app porters have matured with the technology. Gestures and pinch and zoom won't work with a mouse but the key point is interfaces designed for a form factor.
UWP on Windows mightn't be a great success but there's no reason a universal toolkit can't serve both. c.f. Qt - a first class citizen on mobile (Sailfish) and on desktop (KDE), while Plasma Active has real potential on postmarketOS.
On Android, where I am typing this message, a good number of apps designed for tablet work surprisingly well on a desktop (Outlook, Apple Flinger, Hot Death, Taskbar, iview, SBS on Demand, Supertuxkart to name a few). A bit more polish for mouse in the form of tooltips, contextual menus, scroll wheels and menu bars and it'd be a nice interface.