An hour to get to New York Manhattan. Not just the airport. You must look at the door to door time it takes.
What is the time you leave home? What is the time you arrive at your destination? e.g. if would go to Paris, when I look at flying time, it would take 55 minutes with a plane from Brussels to Paris.
By train it would take 1:31.
However I do not live at the station nor at the airport. And those will not be my destination. Say I would go from my home in Leuven to the Eifel tower.
Taxi to the airport : 20 minutes (If there is traffic, make that an hour)
Time before departure : 1 hour
Flight 55 minutes.
Getting out of the airport : 15 minutes
Taxi to the eifeltower: 36 minutes
Total time: 3h06 without any trafic. With trafic, add 1 hour easily.
Train: Walk to the station 5 minutes
Train from Leuven to Brussels, change to train to Paris and arriva in Paris: 2:00
Bublic transport to Eifetower : 35 minutes
So even now the train is already faster. And these trains "only" drive at 320. I also have taken a taxi, instead of parking and loosing extra time for that and picking up a rental car.
To compare: by car it is 3 hours and 20 minutes. Yes, I am aware that other people do not live 5 minutes walking away fron the train station. Yes, YMMV. The thing is that you need to look at door to door times. I have not even looked at prices. Lowest price I saw to Paris was 29EUR (31.13USD)
And if you are interested, I could be in London in 3h30
Websites I used are:
Google Maps in Classic layout