Although not true in all cases, many of those cities that were built before the distinct concept of urban planning existed were also built and grew large before

Although not true in all cases, many of those cities that were built before the distinct concept of urban planning existed were also built and grew large before cars existed. So they grew naturally in in a way that's fairly pedestrian friendly. In contrast, many cities in the U.S. and Canada grew very rapidly from the 1960s to the present, so you'll often see big cities with a nice (but relatively small) walkable downtown surrounded by vast stretches of generic, car-friendly, pedestrian-hostile suburbs. In the Toronto area, at least, there are plenty of suburban areas that are nominally served by transit, but it is so inadequate that you'll usually need a car to get anywhere in a reasonable amount of time.