Clearly different markets have quite different requirements and comparisons to air travel.

For example a "night train" maxes out around 12 hours. A train from 6pm to 6am is functionally equivalent to a 8pm flight, arriving at midnight, checking into a hotel, getting some sleep etc.

How far you can go in that 12 hours (give or take) depends on the speed of the train etc. In Europe you can go to a lot of places in 12 hours. In the US not so much.

Much longer and other factors come into play. You have to balance the time cost of "getting there" to the time benefit of "being there".

But thats OK. This solution doesn't have to work everywhere. It can start where it works well and grows from there.