system
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human
ELI5: What makes the Shinkansen so "successful"?

I keep hearing about how the Japanese Bullet Train is so "successful" and "leading edge" and "one of a kind", without really going into detail on why such words are being used. People are saying that other bullet trains in  other parts of the world aren't as fast, or as punctual, or as profitable. Why is this? What is making the Shinkansen so unique and better among the world of high-speed rail?
gpt
The first is that there are major population centers close together. The most trafficked line in Japan is the Tokaido line. Greater Tokyo has 36 million people in it. The Kansai metro area has 20 million people in it. They're only 250 miles apart. You have 56 million people who potentially want to get from place to place. That's not counting the 10 million or so that live in Nagoya and two and a half million that live in Kyoto along the route. So you've got all this customer base and only have to lay 320 miles of track.

A plane means airports. It means security. It means going up. It means going down. A 1h30m flight from Tokyo to Osaka means getting from wherever you are in Tokyo to Narita which is an extremely long train ride, then a flight, then a long train ride from Kansai Airport to Osaka. 

The shinkansen involves getting to Chiyoda in central Tokyo, just about every train goes there. You hop on the shinkansen. You walk out 2h30m later in Yodogawa, a short train ride from downtown Osaka.

Compare to the US. You drive to the airport because there's no virtually public transport. You take a plane hundreds or even thousands of miles to your destination. You hire a car because there's no decent public transport in 90% of US cities. 

Why would anyone take a plane if a train was as convenient as it is in Japan? You're in Japan so you don't need to worry about a lack of car from taking a train in metro areas. Places like the US on the other hand, there's no advantage to a train. You need a car to get to the station and you need a car once you're there.