The Natural Course of Evolution
Hiller, de Lackner and Bensen were the 3 companies that released prototypes. Some accidents and safety concerns later, the idea of these Helivectors / Aerocycles were scrapped. Today, the one and only prototype of this fascinating experiment is ensconced in an aviation museum. But the concept was definitely a stepping stone for theaircraft technology that evolved.
Source: https://www.fastaviationdata.com/yesteryears-flying-platforms-and-jeeps/