Because ramp launching consume the entire flight deck, aircraft are launched at a slower rate than a catapult equipped carrier. Also, ramp equipped ships cannot launch fully fueled, fully armed strike aircraft. Typically, they launch with weapons and low fuel. This requires them to take on fuel once airborne. All this makes it very difficult to assemble a strike package of aircraft on a ramp equipped carrier.
A US Navy catapult equipped carrier can launch a fully fueled, fully armed strike package very efficiently. No other navy can match it.
interesting. thanks