I don't have the vacation time or the personal wealth which would be necessary to take the time off I would need to travel by some other means between NYC and the island of Trinidad, where my sister lives.

See, the way i look at it is, maybe Americans should have more vacation time. The fact that most Americans can afford air travel is probably one of the reasons employers allow less vacation time than in other parts of the developed world.

I doubt that rapid air travel will ever be entirely eliminated. I think though that in the coming decades it will probably become too expensive for most Americans.