20-Year Prospect
A world without city planners would be as chaotic as one without law enforcement. Without city planners, nuclear plants could pop up next to schools, natural resources would be completely paved over, and you'd be helpless trying to stop your neighbor from lining the street with junked cars he plans to get around to fixin'. Residents of a new community would turn on the shower only to discover that the developer knows more about houses than water and sewer lines.
Even more important than "here and now" code enforcement is the planning aspect of the city planner's job. Long range plans have to be developed in order to ensure places to live for a growing population as well as where they'll work and shop and take their kids to see what little left of nature there is. Certainly, the position will change somewhat as the demands of the world change.
There even may come a time when those utopian societies of science fiction become models for building America 2.0.
In some circles, that "tomorrow" is going on today. NASA and other organizations that have their eyes in the stars are already trying to envision what communities will be like in space stations or on other planets. How do you feel about relocating? We hear Mars has beautiful summers.