Breaking an invasion by destroying its lift

How much of an invasion fleet must be destroyed to make the invasion collapse?

Destroy the landing craft and personnel carriers that deliver the force ashore, and the invasion can lose the lift it needs to continue.

An invasion depends on the craft that carry troops from ships to shore and continue moving personnel into the lodgment. Destroying enough landing craft and personnel carriers can break that link even if larger warships remain afloat. Transport capacity is the important measure here, not an abstract percentage of the invasion fleet. Amphibious operations can fail when their delivery system is lost.