I don't think bitcoin will become a world currency, at least in the short term. We all know that bitcoins can be used as a way of payment, but Fiat is still the mainstream way of the world, and it's hard to get a share in the payment field without the support of national policy.
I am sure that bitcoin will be a global currency, which is accepted by all countries in the world, even though it takes a long time but I am sure it can be achieved, but it is not a bitcoin will replace the FIAT currency