When we decide to store Bitcoin assets in an exchange like the one you mentioned, of course, there is a very high risk of being hacked and the like. To be safer, it is indeed to store it in an external wallet like Ledger or others. But if you don't have a tool like that, we can also store it in Electrum like I do. For now, the two markets above may still provide very high security and asset guarantees because they have market insurance guarantees and others. But in the long term, no one knows how secure the exchange is. If we look at past history, several exchanges that used to be big and had high reputations have also had problems.
Storing in a wallet like Electrum may be safe, but it depends on how well the user secures the device they are using,
how to maximize security and not be careless, it all depends on the user, because it is very vulnerable to hacking.
Some of the big exchanges I mentioned are still good enough for now, not for the long term.
Remember that some of the big exchanges in the past ended up collapsing to the detriment of all their users,
today's big exchanges are even easy to hack by hackers, so be careful.