Visit Japan (or these days China) and you will understand.
This reminds me of people who say, "What's the big deal about electric bikes?" Ride one and you'll know.
See what Japan and China are doing WRT rail and you'll know.
The trains run very frequently, with reasonable fares. It looked to be completely sensible and fast to live in an outlying city and take the train into a larger one for work, whereas the idea of catching a commuter flight from a smaller outlying city into a major metro area in the US (or likely anywhere) is almost completely untenable -- too expensive, too time consuming, too irregular, and too much hassle.
https://www.japan-guide.com/g17/2361_01.png
Subway maps cover cities to insane details.
And at least for the able bodied, bike shares pretty much make up for it in the short term.
PDF: http://www.jreast.co.jp/e/routemaps/pdf/RouteMap_majorrailsu...
And unless you're (statistically) fairly short and thin for a westerner, you won't fit in anything.
But hot-damn does looking out the window at Fujisan while doing 300km/h do a good job at distracting you from having your knees around your ears.
Before I extol the virtues of the train system in Japan, there is one thing that you have to understand first. It is expensive compared to transit services in many North American cities. As far as I know, it's not subsidised by government, so you have to pay the full cost. The main rail system is owned by Japan Rail, but they are operated by individual companies -- each with a monopoly in their own area. Additionally, there are "private" train companies that both own the lines and run the trains. If you live in a very rural area (and it wasn't screwed over by the bus companies), you will almost certainly be using these private lines. If you want to go to a big city, it usually means that you have to transfer. Luckily the payment options are almost completely harmonised -- at least on the regional level. You can get pre-paid cards that work for all the companies in your region (with a very few exceptions).
I live in Shizuoka prefecture. To take the bus a distance of about 30 km it costs about $10 US (also not subsidised). To take the train, it's a bit cheaper (about $7). If you take intercity busses, the relationship switches. A 200 km bus trip costs about $30, while the train will cost about $50. However, the intercity busses only travel about 4 times a day, while the trains come every 15 minutes.
The main difference between the train and the bus is convenience and speed. The trains are quite fast. I often travel to Hamamatsu city from Kanaya city by train. Due to circumstances, my wife goes by car. I beat her every single time -- sometimes by hours. By car, there are lots of unexpected events: accidents, traffic jams, etc. On the train, there are very few -- really just suicide attempts and I haven't seen one in our area for years.
In Japan the trains are on time. Very, very, very occasionally the train will be 1 minute late. Once a year it will be 2 or more minutes late. Seriously, if the train is not on the platform 30 seconds before the scheduled departure time, people are looking at their watches in disbelief.
Part of this is because the trains are set up so that freight is generally able to pass and be passed. On private, rural lines, there is never any freight (though the trains often carry mail). Also the trains are all in good shape. I've literally never been on a train in Japan that broke down. When I lived just outside of London, the trains would break down every week at least. One of the other main points is that theft in Japan is virtually unheard of. When I lived in the UK, I heard that one of the reasons the signalling constantly broke down is because people would steal the copper cables for scrap. Culturally, this just doesn't happen in Japan, so it's a consideration you have to keep in mind if you want to emulate Japan's success with trains.
While my wife has a car, I don't like using it. If we go anywhere, it's usually by bus and then by train. It's only if we need a car at the other end that we use the car (for example, when we go to Hamamatsu, my wife takes the car so that she can take her mother shopping, etc). Because there is no train where I live, I end up always taking the bus.
Even though Japan is a country where punctuality is almost taken for granted, busses are not punctual. They suffer from the same problems that happen everywhere -- busses are really hard to predict. Sometimes the road is clear, and sometimes it is not. The busses usually end up being virtually randomly timed by the time they end up in the middle of their route. I almost always miss my connection at the train station. Because the bus comes every hour or so, it means I usually have to plan very carefully to ensure that I arrive on time. Often I end up arriving an hour early just to make sure I get there on time.
Before I got married, I went out socially a lot more. I discovered that even though the train station is 20 km away, it was faster (and more predictable) for me to ride my bike there, take a bath at the nearby hot springs and then go to the city by train than it was to simply take the bus there directly. This is where I got my love of cycling (and hot springs!).
As I alluded to earlier, a lot of the reason that Japanese trains work is due to Japanese culture. For example, companies that get a monopoly will rip you off, but only by so much. They truly have a sense of social responsibility. The UK moved from a national rail system to something similar to what Japan has and from what I can tell, it completely broke their rail system (I'll probably get some argument about that). However, from my perspective, it's pretty clear that rail is simply easier to make work well than busses. It doesn't necessarily follow that any area building a rail system will make one that works well (I come from Canada and though I love trains I am never going to give any more money to Via. Ever.)
You should try one in the Western Japan. My daily commute on Hankyu line during rush hour is generally 2-3 minutes late every day that I usually plan for it to be late. And JR West is not faring very better either. But we do look at our watches, the departure board, and back at our watches in disbelief, yes.
Sounds like a rare victory of the good over its old nemesis, the perfect. I believe that a social environment that can pull this off will have a clear edge in many different ways, e.g. government can work so much better when it can be trusted that power abuse, if it happens, won't be excessive. Much better than pretend-saints who really aren't.
Optimism mandates that it should hopefully be the latter. It doesn't take much imagination to assume that celebration of ruthless, "take everything you can" types could (in theory) also be minimized in larger, now mixed communities.
In a train you're simply transported sitting down. You can text, have a face to face conversation, look out the window, go to the toilet, buy reasonably priced drinks, read or work as you fancy. The occasional change between trains is a stronger punctuation in your journey than your car leaving the freeway, and still only requires a few minutes of cursory attention every now and then.
Edit: I didn't even mention the timing aspect! In Japan you could get the same train every day and arrive on time every day. Commute on the roads and you will always be wondering when exactly you will get to work/home and what you will do with the little random slither of spare or lost time. Of course, the accelerator pedal is right there so you always have the option to drive a bit more aggressively, so you will consider it every now and then, rather than thinking about something more meaningful to your life.
I was living in China for the last 6 months, you can just show up to the station without plans usually and book a high speed train ride 5 minutes before you go, where you'll be whisked from Xi'an to Beijing, a 13+ hour, 1,000km drive (about the distance from Boston to Cleveland), in 4.5 hours, with huge, comfortable seats, panoramic views of the countryside flying by at incredible speeds, and almost nothing will change your expected arrival (traffic? forget it, delays? pretty rare). You get clean restrooms and food and almost no time wasted at security, no worries about checked baggage limits and fees, and the ability to rebook for 10-20 minutes from now if you miss your train, all of this for less than $80?
Imagine if you could on an afternoon you decide that you want to go to Miami from Charlotte, and you can just casually get up and be there by dinnertime without going broke? It's terrific.
Or if you're more into regional transit, you can go from Suzhou to Shanghai, a 2 hour drive, within 30 minutes for like $5 without planning, similar routes which expand access to Shanghai within an hour's reach of over 120 million people.
It allows you to live in a small, isolated city in the countryside, yet be served by the huge scale airports and business of a megacity, with only a small fee and short time on a comfortable train where you can work, read, meditate, rest, or whatever it is you want to do. It expands your possibilities and brings equality of access in ways you wouldn't realize until you are a part of it.
In comparison with buses, for longer distance it definitely makes sense. For travel within cities, higher reliability (eschewing traffic and potential for accidents), very high capacity, comfort (no abrupt stopping and going, for modern systems at least; also less likely to experience motion sickness, which makes reading, etc easier), speed (think express trains in NYC or being able to cut through very busy places), and from some people's perspectives, increased property values, are all good reasons for it. But it is true, you get 80% of the way there with buses probably.