Digital money always has more potential than cash or paper money. It is used all over the world.
Not definitely, there are countries who doesn't have access with internet. Even if they do, there are sites that were being banned, others have restrictions. Large nations such as China were keen to banned cryrptocurrencies, Bitcoin in general. And with China's population that is over a billion, that's 1/4 of the world market cryptos were losing. As long the awareness of general public increasea, there are institutions, financial and governments that will take such actions for Bitcoin to not take fully over with fiat money. Yes, the potential with cryptocurrencies is given, but as long there are people who don't have any interest with everything going digital, cash or physical money will still be better than Bitcoin.
For some developed countries physical money is not too popular, because city residents prefer to bring virtual money in comparison with physical money that is not too simple, but different things with people who are in the country who do not understand about virtual money they prefer to carry physical money, so for now the virtual money or bitcoin is more popular in comparison to the physical money because the developed countries have a lot