Why LVTs were essential in the Pacific

Where did LVTs fit into Allied landing forces, and why were they used less on D-Day?

Their ability to cross reefs made them critical in the Pacific, while Europe's different beaches and plentiful conventional craft made them less essential there.

The LVT could cross reefs and difficult approaches that stopped ordinary boats, making it central to Pacific island assaults. European forces already possessed large fleets of craft capable of bringing tanks ashore at beaches such as those used on D-Day. LVTs appeared in European operations, including later river crossings, as a supplement to the theatre's core landing system. A later comparison puts their Pacific ubiquity and utility alongside the Sherman tank or Jeep. Geography made the same vehicle essential in one setting and optional in another.