Historically people placed business like buildings around town centres, as these were easy to reach. Lawyers, accountants, doctors and so on were supposed to be within walking distance. But these days this is becoming less and less practical, as everyone including back office employees, software developers, analysts, and other non customer non reach essential staff is crammed in those places. I seriously think planning should be made such way that any non essential business activity should be done outside cities. Downtown areas should be focused on face to face essential staff and the rest of the city on life focused businesses (restaurants, cinemas, and so on). The cities are planned at the moment is archaic.