BTC was created because one day people will no longer believe in Fiat/physical money. Because it is prone to corruption, etc. With BTC, all transactions will be clearly visible because they are in digital form. Wherever the money goes, we will definitely know what its purpose is and what it is used for, and with Bitcoin we can create financial freedom in the future, that's the most important thing.
I don't want to disappoint you but I bet bitcoin will have no impact on fiat, and it will never go away unless governments decide to eliminate it and replace it with a better version of fiat. We will even continue to rely on fiat even if bitcoin becomes popular globally, as long as fiat remains the main currency, the measure of value of the world, we will never get rid of fiat. Also, Satoshi did not create bitcoin to replace fiat or encourage people to abandon fiat, it is just an alternative that exists alongside fiat and the banking system.
How will Bitcoin give us financial freedom? It can only help us reduce our dependence on the government, help us protect our privacy to some extent.
In terms of investing, becoming rich and financially free by investing in bitcoin is not as easy as we think. You cannot become rich by just investing a few dollars and thinking that it will give you millions of percent returns, that is not true anymore these days.