Unfortunately, I say this as a train lover. They require a lot more infrastructure than planes and will always be at a disadvantage because of that. You can set up an airport pretty much anywhere and make it reachable by pretty much anyone. Whereas with the train, you need a dedicated line from point to point that you will commit to maintaining through hell and high water.
There’s also the problem that in many countries, we are deliberately neglecting our train infrastructure and not investing in high speed alternatives that could compete with an airline over shorter distances.
All of these factors combine to make individual trips less efficient over train. I had to cross the United States this week. To do so by train would have taken me 4 days. Doing so by plane took me 6 hours. Nobody would choose a 4-day trip over a 6-hour one unless their goal is to look out the window a lot. Which is perfectly valid. But most people don’t look at traveling itself as the experience. And in this case, I had a particular event that I had to attend.
I say this as somebody who cannot drive. And I say it with all the love in the world for public transit. Public transit absolutely cannot get you everywhere, at least not if you expect to be there in a timely manner. The vast majority of America is suburbanized, the worst possible environment for buses.