Could A Rewinged, Reengined 737 MAX Compete With The A321XLR?

In a word, no. Here’s why: The baseline 737 configuration has proved to be remarkably resilient for a 55-year-old design with 13 major derivatives and more than 10,500 deliveries and counting since 1967. Conceived initially for short-haul routes, the aircraft was designed with engines mounted directly beneath the wings rather than underslung on a 707-style pylon. This enabled a shorter, inward-retracting landing gear and placed the fuselage lower to the ground—making ground-servicing access easier at regional airports, most of which at the time lacked skybridges and other elements of the new jet-age infrastructure.