If bitcoin goes mainstream, all the current problems will disappear. It will become like fiat, just a digitized version.
It can't be FIAT, since as per definition FIAT money is money that's been issued by a centralized entity and is destined to be the currency
as per law. You also can't exert financial controls, to e.g. counter inflation, like you can with FIAT, since you can't regulate or control Bitcoin in the same way as you can with FIAT.
Maybe not technically fiat as tesco said, but If the government controlled enough of it, couldnt they exert the same economic controls they could with fiat?