Well, for one, if you infinitely extend parallel lines running along element edges, they will either converge on a horizontal plane projecting out from the viewer, or at a vertical plane extending at a right angle to the the horizontal plane!
Shouldn’t it look like this?
I mean, come on Vasari! How hard is it to keep your lines parallel? Now my working views have all of this sense of depth and space. Urgg!
AND, unlike Camera views, that are not editable, my perspective view is all cluttered up with dimensions and controls.
So now I’m all, like: “you want me DESIGN in this view or something!?!?”
Answer: Well . . . yeah. That’s kinda what we’re shooting for.