New York JFK can be a 1 and a half hour taxi even on a good day so bear that in mind. I never understand why the ATC in the US cannot let aircraft leave the stands in order, and not just have them line up..... the wastage of fuel and passenger comfort seems to not be important to them.
As the authorities have no control over when airlines schedule their flights - airlines cement their positions at airports by control over gates and terminals, in contrast to how Heathrow and other European airports operate. So they all leave the gate that the same time to depart.