You seem to forget. The discussion isn't A321XLR's v 737-10 Max. The XLR's were bought to replace the 757's. Despite the improved economics of both planes, neither can do what the 757 can. Heavy, short fields, while full. Granted this isn't the majority of the 757 missions, but the 15% remaining that won't be able to be done until Boeing designs the new narrow body. Not another stretched guppy.