Tell me please, what great, potentially revolutionary investments you can make thanks to the access to fiat?
Well, pretty much none. The opportunity to do such a thing is given basically only to the investors that have big amounts of funds ready to get invested.
In BTC world, you can make thousands of investments that are legit and profitable: and you usually can use just s small amount of money for that purpose.
Both currency are good and they both have strengths and weaknesses. Bitcoin has strength that cannot be seen on local currency and that is the accessibility without boundaries and an increased profit due to volatility but its weakness is in areas without internet and to people who does not accept bitcoin. Local currency can be used in any parts of the country with or without internet but you dont get a leverage by holding it in your pocket and it needs to be exchanged to dollar and to other currency when you travel around the world.