Why a world without Harrier still gives assault ships launch aids

If the Harrier had not been invented, would US Marine Corps amphibious assault ships receive catapults?

Probably some launch aid, because the Navy would still want the option to operate heavier aircraft from its assault ships.

Removing the Harrier does not place amphibious assault-ship design solely in Marine Corps hands because the ships and their aviation systems remain Navy equipment. Some launch aid, whether a catapult or ski jump, would remain attractive. Such equipment would let the Navy move heavier aircraft onto and off the ships when missions changed. Institutional ownership and fleet flexibility matter as much as the presence of one vertical-landing aircraft.