As others have already written, rumors say that such investors still choose custody options that are supposedly based on cold wallets and therefore should be beyond the reach of hackers - and most CEXs claim that only a small part of the cryptocurrencies they keep for their clients is in hot wallets.

I would conclude that large and ordinary investors consider CEX as some kind of crypto bank, which of course does not make much sense when it comes to Bitcoin. Although such funds are always at risk, perhaps considering the knowledge of these people, it is a safer option than non-custodial wallets. Being your own bank is not easy and carries with it great risks, and sometimes it is much easier to leave those risks to others.

No matter how we look at this question, the fact is that there is only one correct answer - that regardless of the custody storage method, the well-known saying "not your keys, not your coins" still applies.