40 of the top 100 crypto assets (coins and tokens) by market cap are ERC20 tokens. Exchanges involving fiat are necessarily centralized since fiat requires a ce

40 of the top 100 crypto assets (coins and tokens) by market cap are ERC20 tokens. Exchanges involving fiat are necessarily centralized since fiat requires a centralized custodian. There are some dollar-pegged ERC20 tokens like Tether (backed by dollars) and DAI (a stable coin) that could allow what is effectively fiat-value <-> token decentralized exchange, but to acquire actual fiat, that can be used in the rest of the financial system, requires interaction with a centralized exchange that has a banking relationship.