Money is already going digital. Many central banks and governments are creating their own digital versions of FIAT, PRIMARILY to keep tabs on everyone and easier to tax as well. It's up to us through the lay people to want to convert our economic prowess to decentralized crypto and to want to use and adapt to it, which will make the real difference. We need to educate our friends and family on growing Bitcoin and other good crypto reserves. If we all got 5 people each year to say put 2% of their money into crypto, we would moon in 5 years from now. Unfortunately, too many of us are lazy and not motivated enough to make this happen, that's our drawback and others are just interested to rip the rest of us off with scams.

I am just wondering would it be possible in the future for the world to run solely on cryptocurrency? Considering that right now there are many people from different walks of life who are using cryptocurrencies in their day to day life. I think right now one of the main limiting factors for world-wide cryptocurrency usage is the world’s governments who make restrictions on cryptocurrency usage. Moreover, I also think another factor in limiting cryptocurrency usage is a lot of people’s lack of understanding of cryptocurrencies as it is a rather new technology to most people.

I think that we can solve most of these problems by educating people about cryptocurrencies and debunking what the mainstream media have done to slander cryptocurrencies.
I honestly think that if these issues a solved then we will probably have more people to use cryptocurrencies worldwide.

What would do you guys think, I’m just speaking (posting) my thoughts over here. Feel free to correct me if I am wrong. I’ just rather optimistic about the future of cryptocurrency usage in the future.

It will become a reality only.
The main hindrance right now is that not everyone on this planet is digitally connected. So you can't expect the transition to happen globally. but it can start from some Asian countries like South Korea or Japan.
The world can run on cryptocurrencies but not the decentralized one. Such cryptocurrencies will be controlled and maintained by the government and central banks just like fiat. It will be just an easier way to maintain transparency and reduce the cost.

It would be a bit difficult to achieve this one with right now, as we are still far too far to achieve mass adoption.

Crypto users ' population is growing, but it's still not enough. Many governments are against cryptocurrencies, so it's really hard to say that running on cryptocurrency is possible for the world.

Just like what you said, there are factors that stop it from happening and we still have to work on that factor in order to finally achieve what we want.

Adoption is very real and is achievable in just a few years. Though for the world to run mostly on crypto? That's doubtful. People will always look for alternatives and in case it comes to that point, we'll look for faster, cheaper way to run things just as how bitcoin is to fiat right now. There's no absolute, we'll always have other options.

Legality is major hurdle also government not allowing for it,Beside the creating awareness about the crypto  that maximum population adopt it.First decade of Crypto was for development and current decade is for adoption.Current also precious for the cryptocurrency,halving of BTC is on way and that will also green signal for the adoption and the rising price of crypto.

I believe people run dafter crypto because they want financial freedom and easy way to transfer their funds globally.  

The world is heading towards a new economic order. Production vehicles were much more valuable in the past. Now the material power can keep the money constantly. This cycle needs to be broken. Cryptocurrency can break this cycle. This is my opinion. It can do so with a limited amount of money and a transparent transfer system.

It would be a bit difficult to achieve this one with right now, as we are still far too far to achieve mass adoption. Crypto users ' population is growing, but it's still not enough. Many governments are against cryptocurrencies, so it's really hard to say that running on cryptocurrency is possible for the world. Just like what you said, there are factors that stop it from happening and we still have to work on that factor in order to finally achieve what we want.