Central banks are based on producing fiat money within controls and according to a corresponding stock of metals such as gold, or a reserve of major currencies such as the US dollar.
As for encrypted currencies, they are not subject to any controls of any kind and are produced by individuals (mining). However, some countries that are subject to economic crisis's or international sanctions have exploited these digital currencies and used them in their favor within controls ; The Venezuelan government issued a central digital currency called "Petro" and linked its price to the price of a barrel of local oil which means linked it to oil and precious metals. Also, China has also issued the Chinese yuan, which is a digital currency different from the decentralized blockchain.
Is it true that cryptocurrencies will weaken the global financial system? That system which is managed by countries with the strongest economies with their currencies that has gained wide acceptance to be traded in financial markets all over the world.
This would have an impact on the global economy and the entry of digital currencies would weaken these countries from their control over the economy if other countries start to follow the same approach as the Venezuelan government, as the currency of these dominant countries used in commercial transactions and which has been linked to the prices of gold and precious metals will face Digital currencies whose printing and issuance are not controlled by any official entity.
If we looked at the positive sides of things, cryptocurrencies can be a great help to a country's economy. It can provide financial services to individuals in countries that are in economical crisis. With the massive inflations in Venezuela, people can use it as an alternative. By joining the cryptocurrency ecosystem, it enables them to store, send, and receive money without relying on traditional banking systems.
Take El Salvador for example, they are the first country to make bitcoin legal tender— requiring businesses to accept cryptocurrencies. They made it like that because according to world bank, only 30% of their people had a bank account in 2017. Thus, hoping that by using bitcoin, it will raise and promote financial inclusion which will help their economy. Still for now, there are many cons like the volatility of bitcoin that is always changing.
Now cryptocurrencies can also do faster and cheaper cross-border transactions compared to traditional ones like wire transfer. By removing intermediaries and transaction costs, it can streamline global commerce and enhance economic efficiency. The things those countries are doing are still new, there might be a big problem now but after a few years, I think many solutions are to be made.