Why catapult fighters were an awkward Italian carrier substitute

Could the Italian Navy have used ship-launched fighters that returned to land bases instead of building carriers?

Only in limited circumstances. The fleet had to remain within range of a suitable airfield, and a single-seat fighter damaged in combat could easily lack the fuel or navigation margin to reach it.

The proposal tries to exploit the Mediterranean's smaller scale without adding carrier recovery equipment. Catapult launch followed by land recovery is theoretically possible. In practice, the fleet's position, the airfield network, fighter range, navigation, weather, and battle damage all have to align. A fighter that cannot return to the launching ship turns every diversion or fuel shortfall into a risk of ditching and losing the aircraft. Local geography could reduce Italy's carrier requirement without eliminating the operational value of a recoverable fleet air group.