Another cause for delay:
Sunfish himself occupying the flight attendants with outrageous demands and neverending whining. Just stay home "mate", and you'll never have to expose yourself to anything that's not "Ostrine".
Like someone said, it's airport capacity that can cause congestion, not which piece of metal we all arrive on if it happens to be at the same time.
Came back to my homebase a few days ago at the same time as three other widebodies. Talk about congestion.