Centralized cryptocurrency exchanges are like banks. There is no absolutely safe bank and no absolutely safe exchange. Because there are a large number of hackers attacking exchanges or banks all the time.
Several centralized exchanges have been hacked (equivalent to billions of dollars in cryptocurrency stolen) in the past.
I wonder if they really got hacked or did they makeup everything to steal investors' money and then blame the hackers. I believe it was not a hacker attack but the project developers themselves did it. Cryptocurrency is a market full of scams and we should accept the risk before deciding to participate. Don't blame someone if we lose our money, because you just need to invest in bitcoins and store them on a non-custodial wallet, no one can scam you.