Definitely!
This is what people keeps forgetting about when they say Bitcoin will soon replace fiat or soon replace the traditional banking system. Satoshi for sure didn't write something like Bitcoin replacing something in the whitepaper.
If cryptocurrencies are only currencies existing, the world will not balance, but existing with fiat currencies makes them perfect, but only the good ones like bitcoin. So, Bitcoin is perfect because fiat are existing. I was thinking how the countries in Africa and poor other countries will be like if no fiat, countries that always devalue their money in order not to deplete much of their foreign reserve, if no fiat, they will all suffer.