The banking system is still in operation and crypto is a different avenue all together. If the banking system is to be replaced by crypto, then what will be the bases for determining the value prices of crypto in fiat. This is because if banking systems die off, fiat dies to since all banks deals in fiat. It will be awesome to have a crypto ban tho. But currently, most countries are banning the use of cryptocurrencies.
Most countries prohibit the use of cryptocurrencies only because they do not understand its advantages and are afraid of the threat of the traditional Fiat currency-monetary system. In progressive countries, people are happy to use cryptocurrencies and blockchain, and this greatly improves the quality of their life.