I don't think bitcoin is ever a central currency. Because each country needs its own currency. Bitcoin should be incorporated as a monetary alternative, we do not have to wait for an idea like OP raises. It is better that bitcoin is independent as always, that we have the opportunity to choose I agree.
If Bitcoin has worked for many of us it is time that more people know how to incorporate it into their monetary resources.
The process has been slow but in my opinion we are on the right track.
The need for new technologies in finance will make bitcoin enter more places around the world.

Just imagine if Bitcoin becomes the world's central currency, looking at Bitcoin's volatility now and looking at Bitcoin's volatility if it becomes the world's central currency, it would be much worse than it is right now, so a lot of people will actually say no, the volatility now is actually high, we can't entrust everything at a currency with this much volatility.

very big opportunity for bitcoin to become a unifying future of the world...

as jack Dorsey said in an interview that bitcoin will become a unifier of the world so he focused on developing a lighting network. when many small countries adopt bitcoin as a legal tender, large countries cannot refuse bitcoin adoption.

Though crypto is already accepted by most developed countries but the question is can we predict the use of crypto as the central currency? The future for that is possible but it will take a longer while, am not sure in this generation maybe next, but the volatility and fluctuations is the major concern to be considered before it adoption as the world central currency.

"Worlds central currency" ? Really? Wake up from your dream. I think such day will never come, or at least not in our century. When two neighbor  countries can not come to an agreement in political and economical question, how can hundred of countries agree to have one central currency? This is simply unreal. And what about pride for a national currency? History? Take US dollar for example. How old it is? It is most popular currency and still not a worlds central currency.

I agree with those who say it's not possible to happen. We live in globalized world characterized by centralization of power in fewer hands which are united in factions, organizations and oligarchies in different parts of the world, but all of them connected by the common goal that is to suppress the regional cultures and individual freedom.
Bitcoin as it is right now looks like a threat to these people. For this reason I don't see why they would consider it as a world central currency. It's more interesting for them to create their own crypto currencies as some countries and big techs are already doing right now.

On the other hand, if these globalists are able to hold at least 51% of the bitcoin supply they could subvert the decentralized nature of the crypto currency, turning it into the world central currency. Although it's almost impossible to happen I think the desire does exist and that is why we see a lot of manipulation attempts in the market. They do this to incentive the weak hands to drop their coins, so the whales can keep buying and accumulating more and more coins within time.

It's a good question that everyone is curious about a certain answer of it. In my opinion, this is not very possible. Because Bitcoin is a volatile cryptocurrency. Maybe its volatility is getting lower in time (which I don't believe so) but the volatility will never be gone. This is the nature of Bitcoin. It's been like that since it was first released. Governments wouldn't lean towards making it legal tender that easy. For now, there are only some developing countries that are aiming to do so. Developed countries are searching for ways to keep their currency's value and they are developing their own digital currencies at the same time.

It might be possible in the future but for now, the chance is very slim. Bitcoin has been getting a lot of restrictions even if there's a lot of countries now who wants to get involve in bitcoin. But the fact that the government personally is not supporting it, then it would be hard for bitcoin to become a world central currency.

And being a currency with high volatility, i don't think it will  serve as a world currency if the value is not fixed. Because as far as i know, its volatility will always be there and might only be reduced if the government start controlling it.

Bitcoin being the world Central currency isn't gonna happen for now. Maybe in the future it has high chance, because of more corporate networks involvement into the usage of cryptocurrencies and development of their own cryptocurrencies tied to the Bitcoin network. As an user mentioned, there are people who aren't aware of digital fiat and there are regions where there is no internet access. Bitcoin needs internet connectivity for accessing. Likewise several hurdles need to be overcome to reach the mainstream adoption through which it can move towards the next level. This gradual move could make it the central currency after fifty years.