I use three 1440p 27" monitors and vertical real estate is still something I'd seriously inconvenience an adorable puppy for more of. If my desk was a little better-shaped for it and I didn't need a place to put speakers, etc., I'd go back to using at least one vertical display.
What I really wish for are 2000x2000-ish square screens, ~20 inch diagonal with minimal bezel, so that I can stack 3x2 of them and get to work at last instead of flipping wasting screen space and head movements on overly wide screens.
Ironically, I do enable them on my tablet, because I don't always have a keyboard attached to it. Tablets generally have enough space for full menus / toolbars, and lacking a keyboard they're arguably the form factor most in need of them.