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.
Almost all developed nations have that protection, but it is not really governments that does it, the banks do provide a special "tax" for that fund, this means all the banks in a nation has a security tax thing, where they all pay the government a certain amount every month, and that money is collected by the government, and then when the time comes for a bank to bankrupt, the government uses that amount to just pay to the people up to a certain amount.
It is never "all your money back" situation, but it could be like up to 50k dollars per person that had money in there, the idea is to save smaller investor, if you have more then you should use multiple banks to make sure you are doing fine in the end and not get bankrupted.