Why V/STOL payload penalties are not only about weight

Do V/STOL aircraft always suffer major fuel and payload penalties?

Not when they use rolling takeoffs and ski jumps; for the F-35B, lost internal volume from the lift fan is more persistent than takeoff weight alone.

A pure vertical takeoff imposes a severe fuel and payload penalty because the aircraft must lift its entire weight on thrust. Ski jumps and rolling takeoffs allow the wing to contribute lift, greatly reducing that operational disadvantage. Rolling landings can recover similar margins on return. The F-35B's more persistent limitation is internal volume: the lift fan occupies space that the A and C variants can use for fuel or weapons bays. The answer separates how the aircraft is operated from the structural compromises built into a common airframe.