Chicago's development happened over decades and does look pretty good and eclectic. Seattle's has been concentrated in less than two decades and frankly looks like shit.
You know what Chicago has that Seattle doesn't: setbacks. Look at that sidewalk. Room for big trees and lots of pedestrians. It's written into Chicago's Zoning Ordinance, but not Seattle's.
Clearly the problem here is those dumpy old buildings to the right of the skyscraper didn't get knocked down so the tower could be be even more gigantic. Just kidding...
I wonder if the owner of the smaller building sold the rights to the overhead space above their building. It's actually a common thing that the developers of large buildings do to keep their views and light.
I'm not trying to be argumentative; I find it strange that you've chosen to live in something you feel shouldn't exist.