For some trips, yes. The travel to the airport and time through security and boarding are fixed. Taking a 1 hour flight from Detroit to Chicago almost isn't worth it when you can drive it in 4 hours, because you've got probably an hour to the airport and an hour of waiting around at the airport to board, then more time at the other end getting more transport to your final destination.
But those same ~2 hours prep pale in comparison to, say, LAX->SYD. :)
Every time I make that trip on the A380, I'm Louis CK for the whole trip. I'm going as far as I can go without starting to come back again in one night and all I have to do is sit here and eat the snacks and watch my choice of movies on the tv in my seat. Bump future.
But those same ~2 hours prep pale in comparison to, say, LAX->SYD. :)