People who have never been to L.A. really have no idea how insanely huge it is. Driving to my apartment from the start of city (before you even get to L.A. county) and having the city just keep going and going and going for two hours and not because of traffic jams is something you have to experience to truly understand.
There is no reason to push and shove and stand in front of the door to get in before letting people out if there is a train every 3 min. Seen the same in Singapore. You arrive at the station, see your train is already there but you dont care. You dont run you dont rush because it doesn't matter. You just take the next one
I've had the same experience in Copenhagen. Their metro is fully automated, and the schedule is published as "one train every x minutes during rush hour, every y minutes otherwise", which is very nice. You just turn up at the station knowing you'll only have to wait that many minutes. The automation takes it to the next level as well, because the trains run on this schedule through the night.