The 757 is a larger jet. Smaller jets have become increasingly popular with airlines. Probably had to do with the flexibility and extra timing / route options t

The 757 is a larger jet. Smaller jets have become increasingly popular with airlines. Probably had to do with the flexibility and extra timing / route options to offer by flying lots of small planes vs fewer large planes. Also, global pilot pool doesn’t matter as much as what individual aurlines’ pilots are certified on. The specific airlines that operate 737s would prefer not to have to retrain their pilots on a new aircraft; if they had to retrain them for the 757max that would open the door to consider the airbus as an equally good option.