My sense, when I first heard of it, was that it was "one dollar one vote", or a system where the biggest whales will control the chain. That said, that's how the existing system capitalist system works, with a hierarchy of banks, so it would probably work.

BTW, the interest rate on USD$ is close to zero not because it's fiat, as you imply, but because they target a low rate of inflation. That's because the wealthy are controlling the system right now, and high inflation harms people with assets. Low inflation harms people who labor and are in debt.