This isn't just skyscraper canyons or suggesting we make every ground floor facade twice as tall all over the park. New Orleans Square and Adventureland are already two levels. Adventureland is low overall but has themed backstage upstairs areas and a second floor queue for Jungle Cruise. Between the height of Tarzan's Treehouse and the depths of the pirates show building, we go from 2 floors of guest areas in new orleans square to, what, 5, 7? That sort of multileveling is ideal, where the programming and the themed environment work together. Tomorrowland too has a tall street wall, the entire interior of the "launch bay" underutilized, and obviously space mountain. Fantasyland and Frontierland are two lands with the least multileveling, though they each have examples (Golden Horseshoe, castle walkthrough, alice if we count dark rides), and they aren't absent of height; the FL facades create beautiful panoramic sky silhouettes, with well-placed roofs, towers and icons all around. Rather than looking at facades, our eye is drawn upwards where the detailing on the roofline is really interesting. Main street has forced perspective in its facades but if the show from the exterior were left alone (aka don't butcher like Club 33), I see no reason why guest areas couldn't be built in to the upper levels of some of those structures when crowd levels demand it.