The Switch uses the tablet part for all the processing, though. Even the same OS. I would love an option like that for iOS, though. Get home, dock your iPhone, and have everything displayed on a bigger screen with mouse support. It would be even better to have a separate UI for that, just like Microsoft is doing.
your post reminds me of the tech shown in Black Mirror (3 seasons on netflix). On a few episodes they dock their phones to their car gauge cluster area, home docking that integrated into the house and much more. This would be awesome if they actually came up with a way to integrate our smartphones into our home by simply docking it somewhere in the house and getting your notifications through your tv, computer, iPad, home automated thingy or whatever. Man if only we were born like 50 years later imagine what we would see. When I was a teen we had pagers and brick size cell phones. I still remember pagers getting taken away in my junior/senior year for going off during class. This is when pagers were the latest and greatest back before they received text and even before people figured out how to spell 80081355 and other dumb numbers that spelled stuff haha.
As far as the ipp they do need to make a docking station that will allow us to connect to a larger monitor and use the apps with a mouse. This would completely take away my need for a mac as far as school, entertainment and daily activities. Only thing this wouldn't fix for me is I would still need a desktop for gaming.