Yeah, but at slot controlled airports, the A380 won't ease congestion. No aircraft would.
Let's say airline X has 16 slots at ORD
They buy and put in service the A380 which means they cut frequency.
Instead of 16 flights they operate 8 now.
Who here thinks they'll give those slots up for a competitor to snag?
Those other 8 slots will be used to add frequency or new service with other aircraft types, probably Rjs.
Congestion is here to stay, we're not going to see FEWER flights even with larger aircraft. Maybe fewer flights to a particular destination, but not overall. Even if every airline out of ORD
converted to the A380, those extra slots would be gobbled up for RJ
service of additional mainline service. The answer to the congestion problem is newer, more advanced ATC systems and runway reconfiguration in the case of O'Hare. Not larger planes.