DEX and CEX are no different, they are just exchanges and if you are afraid of losing assets in both then keep the funds in your personal wallet as it is safer from any risks. But CEX like Binance and Kucoin completely cover funds for hacking cases and will DEX do the same?
On DEXes, you do not necessarily need to open any account, you can swap/exchange on your noncustodial wallet directly. For example, you can use DEXes on wallets that support it, like Uniswap as an example, you can just swap directly without any custodial means on wallets that support it like trust wallet on mobile and metamask wallet on laptop, another DEX is Binance dex. You have the private keys of your addresses, there are many noncustodial wallets that support DEXes, in a way you will swap from one coin to another using noncustodial means like I explained. Even, on trezor, you can access binance Dex.
There are many DEXes you do not need kyc, and in which you will make use of address that you control its private key to swap/exchange from one coin to another. That is why most people that are privacy concerned prefer to make use of DEXes for exchaging from one coin to another rather than custodial means. DEXes are noncustodial means of exchanging from one coin to another by design, using proper one will make this to be fulfilled.
