....... and then there is the need to carry sensible alternate fuel when you pitch up on the east coast of N America during the winter - let alone the ability to hold at destination.
Sensible alternates can be considerable distances when the weather is against you - I once heard someone, inbound to JFK, diverting to Miami. It may have been for company reasons (the diversion to MIA) but there wasn’t much choice in the top right quarter of the US that day.