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 hardware wallet etc.
this is the link of the news :https://cointelegraph.com/news/coinex-crypto-exchange-suspected-hacked-crypto-moved
There are many types of wallet options for storing coins. Those with experience suggest open source wallets among the many existing wallets to use.
Hardware wallets are known to be more secure storage although I haven't used them. Users who usually make transactions regularly are more ideally suited to using a software wallet.
We have often read news about exchange hacks, so their advice against storing exchange assets is something that can be justified.