But we can't deny its more safety to store in the bank than those CEX since those legal institutions cannot easily break away and turndown there depositors since they get easily caught up also there's insurance will cover to those people if there's bad happens on the bank. In Cex we cannot do anything if they turn scam and its not really a good comparison since bank is more legitimate option to store our fiat while CEX is been discourage to do it if we are a holder since to many risk and the owner of that can control their site then decide if there users can withdraw or not. But the end of end still we should not trust any crypto site even if they are trusted or not due to many possibilities it could possibly happen.
Well also banks can close down but normally you are always more protected and even if they fail, the government backs up your funds to a certain amount (at least that is the case in Belgium). These last couple of months, a lot of CEX have been closing down including ones that I didn't really see coming such as Bittrex so we always need to be carefull and not store too much crypto or money on these sites.