When you say most places, I assume you leave out most of the world in this? The number of countries with broad complete train networks is small compared to the land mass of the earth inhabited by humans. Even considering urban areas, most people don’t live in London or New York or Tokyo. They live in a city like Jakarta, Dhaka, Mexico City or Lagos. Even Bangkok which has the MRT and Skytrain only services the relatively affluent areas with service, everyone else is car bound.

Most urban US cities have some attempt at an urban train network, and most significantly more useful than Seattle. The issue is typically more of funding and willpower - major infrastructure in an established city is expensive and disruptive to the point most don’t want to deal with it. Additionally the feeder transit infrastructure tends to be weak enough that the daily practicality is low because you have to live right on the line and your destination must also be. Otherwise you’re driving in. Finally the urban planning for surface roads has been well enough structured that the trade off for time saved in public transit doesn’t make sense. You spend time walking and doing transfers in excess of double a driving time.

Is that a flaw? If you electrify the cars to minimize pollution, automate their driving to reduce risk, ensure they collaborate to improve efficiency, I’m not sure I buy the argument any more.