In my opinion, that will not happen, because bitcoin was not created to become a reserve for the world economy. Bitcoin is decentralized and independent. Governments in the world are unlikely to accept bitcoin as part of the real economy. This cannot be combined because this basis is different.
This makes sense. Governments wouldn't allow a decentralized cryptocurrency such as Bitcoin take over their economic supremacy. All they want is to exercise authority over the supply and issuance of money. As such, Bitcoin in its current state cannot fulfill the requirements to be classified as a reserve currency of the world. If at some point within the future, Bitcoin becomes centralized, then such scenario will happen by then.
Otherwise, the USD would continue to dominate the world as a reserve currency for quite some time. Speaking of centralization, Ripple (XRP) has a better chance of becoming the world's reserve currency than any other popular crypto known to date. It may not be directly XRP itself, but it could be the same USD or EUR issued within the XRP Ledger (obtaining the full benefits of a blockchain). Despite this, what matters is that Bitcoin is the "People's Currency", which will remain that way if it preserves its decentralization. Just my thoughts
