The $175 billion figure travels because it fits in a headline. It is also the wrong unit. GENIUS-era stablecoins are not a market cap story. They are a reserve-composition and redemption-rail story.
What changed is not that dollars can be represented on a chain. That has been true for years. What changed is the political permission structure around who may issue, what they must hold, and which federal desk gets the call when a run starts at 2 a.m.
Issuers will sell simplicity: one token, one dollar, one audit letter. Operators should sell the plumbing: who is the custodian, which chain actually clears, whether an agent can pay a 402 without a human in the loop, and what happens to yield when the reserve is forced into cash-like paper.
UnyKorn reads this as a collect-rail problem. If the token is cheap to move and expensive to explain, the desk that explains it — and meters the explanation — owns the margin. The map stays free on /llms.txt. The body does not.