Why did early jet airliners need stronger and larger airframes?

Early jet airliners required stronger and larger airframes to meet specific economic and operational demands of the new propulsion technology.

The need for larger airframes was driven by the requirement to carry a greater number of passengers, which was essential to make jet aircraft economically viable. Simultaneously, these airframes had to be significantly stronger to accommodate a pressurized fuselage, a necessity for cruising at high altitudes where jet engines operate with greater efficiency. This structural integrity was also vital to withstand the repeated stress of transitioning between low-altitude takeoffs and landings and high-altitude cruise conditions.1

Beyond size and strength, the integration of jet engines necessitated other major structural modifications. Designers implemented swept-back wings to mitigate the drag increase associated with approaching supersonic flight. These advancements in airframe design were critical to successfully transitioning from reciprocating engines to the high-performance capabilities of the jet engine.1