The registry admits only two chains because the thesis is specific: Bitcoin forces the choice, and demand re-coordinates on the closest credible proof-of-work substitute. On the distance ladder — how near a substitute sits to the job of permissionless finality — banks and cards offer permissioned finality, stablecoins add counterparty and perimeter risk, proof-of-stake L1s are a different security model, and only proof-of-work substitutes clear the same job on a different chain. In open-source money, code is copyable but coordination is scarce, so demand concentrates on one substitute instead of scattering. Whether Litecoin actually retains that flow, versus the control set of BCH, DOGE, DASH, and XMR, is a registered claim that has not been measured.