They burned through $5B of 1999 dollars, building out a network in 23 cities, and had effectively zero customers. Finally shut down in 2001.
All their marketing was focused on "mobile professionals", whoever those were, while ignoring home users who were clamoring for faster internet where other ISPs dragged their feet.
Today, 5G femtocells have replicated some of the concept (radically small cell radius to increase geographic frequency reuse), but without the redundancy -- a femtocell that loses its uplink is dead in the water, not serving as a relay node. A Ricochet E-radio that lost its uplink (but still had power) would simply adjust its routing table and continue operating.