Banks do not look reliable because they are controlled by the state. But some part of the assets may be kept in the bank.
Keeping everything in cryptocurrency is quite dangerous. Assets need to be diversified.
Keeping money in banks is safe but there are many people who prefer investing in cryptos rather than banks. Although crypto is dangerous if you understand the correct position of the market and invest in the right currency like bitcoin it is never dangerous. The government has to pay tax to keep money in the bank there is no such hassle for crypto.