Originally Posted by WineCountryUA

Yes, the use of busing does occur but is not common. It can be used if an aircraft has landed at an alternate airport, for example. Busing from WAS-NYC is pretty unusual but for some, it may have been the preferred situation. A couple of hours of busing may be preferred vs being pushed out to the next day for a flight.

I have been bussed (2 hours) from SFO to a nearby UX outstation when weather prevented flights.

Separate tickets always carry a risk of a major delay -- it is easy to get comfortable with the idea air travel as regular as the trains in Japan or Switzerland, but it isn't.