the average 777 flight is only 5 hours long?
Why not? A lot of operators use the 777 as a short haul aircraft. That's the beauty of it - if you allow me this word in this context
-, you can use them in a mixed environment of short, long and very long routes. I know BA does, US operators, SIA, Thai, JAL... 747 also were used as short haul aircraft.
Dani