IF energy storage technology evolves to a point where such urban air transport is possible, they wouldn't be building cheap airplanes using mass production; general aviation as we know it won't exist any more, for multiple reasons. First, the technology that would make such air transport possible would also completely eliminate gasoline fueled ground vehicles, and without the automotive market supporting the gasoline infrastructure, aviation gasoline would also cease to exist. The market would just be too small to operate a refinery and distribution system. Second, if such large numbers of flying cars (might as well call them that) come into existence, they would have to be fully automated and air traffic control and airspace would have to be reorganized to let them move safely... which would eliminate the ability to fly a manually controlled conventional airplane anywhere other than the remotest areas, if even there.
But the technology to make it practical doesn't exist, and is not likely to exist, absent a major breakthrough in nuclear physics. The limits of chemical energy storage are well understood, and there is nothing known that comes even within an order of magnitude of gasoline or other existing hydrocarbon fuels.