@ernie shout out to the idea microsoft was trying at the tail end of Windows phone.
I never tried it, but you could plug a Lumia 950 into a dock and suddenly you would have a desktop Windows experience running from the phone.
It kind of sucked because it was so early into ARM on windows (and has that actually gotten much better?) But the idea of your phone being your PC that you slot into laptop frames or even a desktop setup was and remains appealing.