This is something that bitcoin was created for so that people can be their own bank because bitcoin is decentralized and it shouldn't be stored in a centralized way. Bitcoin should be used for the purpose that it was created for which is to get rid of a third party. Keeping your bitcoin in an exchange is like you have kept you bitcoin in a market place where it will be vulnerable to attack. Just take note that the moment your coins gets into the exchange, it is no longer yours, and the figure that you are seeing means that the exchange is owing you that amount. For instance is you keep 0.5btc in an exchange, the exchange is owing you that amount because your coins have been borrowed out. The risk in storing your coins in an exchange is higher than you being your own bank, when you use a self custody wallet like electrum, blue wallet as they are easy for beginners. The exchange can sell out your information to the government and your account can get frozen. The exchange can get hacked, bankrupt or go on exit scam, but when you are your own bank, if you take proper precautions on the safety of your wallet, you will be safe.