Charlotte is not going away as a base any time soon. Airports, like Airlines, have internal costs which allows the investment community to compare airport operations for efficiency etc. Airline cost is CASM or Cost per Available Seat Mile. Airports have Cost per enplaned passenger.
Cost per enplaned passenger (CPEP) is defined as all landing fees, airside usage charges, fuel flowage fees, terminal rents and other airline payments to airports divided by enplaned passengers. The median CPEP for all airports in a recent survey of airport rates and charges was between $5-6, with large hubs having slightly higher costs than small and medium hubs.
https://trid.trb.org/view.aspx?id=664273
Pittsburgh, a former US Airways hub at one time had an enplaned passenger cost approaching $15.00. For 2017, it's: [ The budget lowers airport rates and charges for the fifth straight year, projecting a cost per enplaned passenger (CPE) of $11.30.]
http://www.flypittsburgh.com/newsro...urgh-international-airport-has-busiest-summer
Charlotte, on the other hand, under the direction of Jerry Orr, decided over 30 years ago to keep the enplaned passenger costs low to stimulate traffic and regional and airline growth. As a result CLT has new runways, and new terminal under construction and the inter-modal rail / air terminal. The CLT cost per enplaned passenger is $1.35 in 2016.
https://www.dwuconsulting.com/airport-finance/articles/cost-per-enplaned-passenger
Airline agreements
Gentry describes 2016 as a good year for Charlotte Douglas because of a significant increase in local and international traffic (see traffic mix below), the continued upward trend in cargo volumes and the “milestone” renegotiation of its lease agreement with the airlines.
http://www.airport-world.com/features/airport-profiles/6265-destination-clt.html
She notes that the new lease agreement provides more “favourable terms” for the airport in terms of airline fees for the usage of its facilities, and paves the way for future expansion without jeopardising CLT’s status of providing the lowest cost per enplaned passenger (CPE) at a major US hub.
Doug Parker knows a good deal when he has one and he is not going to doing anything to reduce CLT. It is the most cost efficient hub in the US. CLT will likely increase, as evidenced by the new terminal construction.