Nick Szabo already knew in his Bitgold design that consensus can't scale to large transaction throughput securely. So he designed a 2 tier architecture:

1. Bitgold itself, the settlement layer

2. Chaumian digital cash - A peripheral payment network

"Money requires social scalability in its design, via security. For example it should be very hard for any participant or intermediary to forge money (to dilute the supply curve leading to undue or unexpected inflation)."

This is why we're paying so much for all the security.