Satoshi created bitcoin to replace the outdated monetary system of fiat but it will never achieve that goal because the government will never let that happen. Plus the volatility of bitcoin surely no one dares to use such a volatile asset in daily life, bitcoin is more suitable as an investment than as a currency.
I disagree with you, because Satoshi never created Bitcoin to replace fiat money than to reduced unemployment and eliminate delay in people transaction. I don't think, Bitcoin will be future of money, because Bitcoin is a decentralized currency that is not control by the government like the way government control fiat money in the time of inflation and deflation which their major power to do all those things is central bank. Bitcoin will remain decentralized currency to fulfill the purpose it was created by Satoshi for the whole world to enjoy.
Many people give their own reasons why Bitcoin is created as point of view, so i believe that Bitcoin have a very good technology and the reason why it's created should be base knowns to Satoshi, so therefore i believe that Bitcoin have its tune. But if i should explain why Bitcoin is being created, from my point i will say that it's a decentralized currency that is made to work in accordance with Fiat currency to add more values and easier way of making money transfer from another continent to another so easy without passing much stress.