Yes, definetly yes!
I am very sure that the crypto currency will one day become a substitute for the paper currency currently circulating. But, it's not Bitcoin (BTC), Ethereum (ETH), and other crypto currencies that exist today. Why? Because they still have the following disadvantages:
1. Volatility
Because the crypto currency currently circulating today (except stablecoin) is still very volatile, this means that it is not feasible to be used as a payment instrument like traditional payments.
The currency must only have around 0.1 - 1% volatility per day, while the currency Uang can experience price volatility of up to 30% in 24 hours.
2. Difficult to use
Indeed, there are now many people who can use crypto currencies, but for ordinary people it is still very difficult to understand and use them. This must be compiled, so anyone can use it easily.
3. Regulation
Even today the crypto currency regulation is still a very big problem for developed countries, and becomes a problem that cannot be solved for developing countries.
Actually there are still many shortcomings of crypto currency to be juxtaposed as a legitimate payment instrument. Therefore, this will be one of the challenges for crypto developers to provide an "exit point" to solve current problems.