Have look at the XRPL DEX. You can trade there with IOUs (for example BTC IOUs or USD IOUs). Works from anywhere in the world since its a DEX and its extremely cheap (no fees) and it can not exclude people.
You still need a way to exchange from and to traditional fiat but that should not be too hard to do. For the most part you can use IOU fiat so they can stay on the ledger ("blockchain").
You still need a way to exchange from and to traditional fiat but that should not be too hard to do. For the most part you can use IOU fiat so they can stay on the ledger ("blockchain").