Unfortunately I bought an LG 4k display from Apple last year (or was it the year before?) for home office work so it'll be a tough sell to buy something new, but this solves a couple of my problems with my home office setup, namely having to put in headphones with a mic for every video call since I use my Mac in clamshell mode, and having an external webcam mounted on my monitor. This is very close to "one cable to rule them all" setup. Maybe I'll just have to save some of my allowance for a bit :P
awkwardly small / awkwardly positioned second display when compared to a regular second display. main display has its own cam. and the external magic trackpad can go front and center on my desk.
the wasted parts get to come out to play when undocked :)