Although this has not happen to our exchange where we put our funds for a long time, this should prove that its not safe to be there for months or years, you have to secure your money, or tokens/coins to your hardware wallet, or electrum wallet etc since you have full control unlike CEX.
Earlier there is a news that Coinex have been hack, where the hacker transfer and drain the wallet, with ETH, Polygon, Tron etc, i think this is the first time this exchange has been hack, i say i have coins there but no value, but if you have lots of eth and others thats is a major concern, since we don't know if they can refund the loses.
so to be safe store your bitcoin and other coins to safe wallet, like a hardware wallet etc.
By now, most crypto investors should know better the risk associated with non-custodial wallets and how stupid it sounds to hold huge some of money in an exchange wallet, This is the most pathetic practice ever and anyone who indulges in such moves has the right to complain if anything goes wrong on those exchanges, in recent time, there have been a lot of scary news around exchange and other services providers like casino who have been hacked and this raised a lot of concern, and also the awareness to hold your coins in your wallet and not on an exchange.