[throwup238]

The 737 and 787 are fundamentally different designs. The 737 is made to be small enough to deplane using stairs to the tarmac at smaller airports while the 787 is exclusively for modern airports with walkways. The 737 is about 12 meters tall and the 787 is 17 meters tall as a result.

That was the driving factor behind the 737 Max disaster. The most efficient engines are high bypass turbofans which are getting taller and taller to fit the main rotor so they had to place the engine nacelles in front of the wings rather than below in order to fit them. This changed the flight envelope and necessitated retraining which Boeing avoided by implementing MCAS which caused the crashes.