Beaching the transport risks the whole lift plan

Why not revive the Second World War LST as the standard modern amphibious ship?

Because driving a large transport onto an uncertain beach risks damaging or trapping a hull needed for later lift; smaller landing craft contain that risk.

Modern light amphibious concepts share features with the older LST idea, although direct beaching has declined. British Round Table-class logistic ships could beach during the Falklands campaign, yet survey information made commanders reluctant to risk stranding or damaging them. A large transport lost on the beach cannot support later landings or sustainment runs. Smaller landing craft isolate that risk in expendable connectors while keeping the ocean-going ship afloat and reusable.