The downfall of trains is that they require track, which require rights of way. Trains are cost-effective if a lot of people make the same trip, and that's after a massive investment cost.
No one in their right mind would fly their small airplane between two cities that were connected by high-speed rail. But if you're going from somewhere small to somewhere else small, trains will never be a cost-effective (or efficient) mode of transportation.
Many European countries disagree.
In the Netherlands (40k km2) there are about 400 trainstations and all of them cost a fraction of any reasonable airstrip and can go to the heart of the town.
No one in their right mind would fly their small airplane between two cities that were connected by high-speed rail. But if you're going from somewhere small to somewhere else small, trains will never be a cost-effective (or efficient) mode of transportation.