America is too big for planes, too. If your transportation solution is flying, now everyone has to get around via endless highways or big, complicated regional airports, and you can only have so many of those. There's a reason why rural areas in North America have completely different politics from urban areas, and why so much of it is driven by a sense of isolation and abandonment. Trains promise to help here because they are able to stop in small places that will never, ever have practical airports.
A good rail network provides a reliable, consistent, repeatable, and straightforward three hour connection from Nowheresberg to the nearest city. Slow, but good enough to feel like they exist in the same planet. Unfortunately, that promise is subtle, and it plays out over decades, so the reward system we've created for ourselves is incapable of supporting it. And thus, we have Amtrak and confederate flags
A good rail network also connects to major airports to give people a range of choices so they can pick the best combination for their travel