When the 3rd world has enough cheap electricity for VR porn birthrates will drop. While megawatt class fusion powered quadcopters and VTOLs will make cheap flying busses extending the commuting distance for cities opening up new suburbs possibly creating a new baby boom in the first world. Eventually just as bacteria get resistent to antibiotics humans should evolve resistance to the antenatal culture of modernity. Fusion powered hypersonic planes and spacecraft will open up the solar system to colonization, and allow generation ships to spread life across the galaxy.
