Fees are static in units

Because nothing is metered, the fee for a given transaction is constant in units of the native asset: the same transaction costs the same tomorrow as today, with no state-dependent surprise and no failed-execution charge. That claim is exactly as strong as stated and no stronger. What a fee converts to in external value moves with the asset, as on any chain. Whether the protocol can offer predictability in value terms is open: doing so would require pricing against something external, which needs an on-chain read primitive, itself an open design item, so the fee model and that primitive are coupled [A]. Until that is resolved, the claim this documentation makes is static in units.