So you wanna say, that PCS and Uniswap are fake DEXes? So what is the normal DEX in your opinion?
Yes, a real DEX never hold any money or coins on a centralized pool/hot wallet, if those DEX do that, then it's a fake DEX. Since real DEX doesn't hold any money or coins, any hack on the sites wouldn't suffer any losses to any customers except the hack can gain access of the site and ask anyone to send Bitcoin in scammer address or asking a private key. Take a look with this case [1] [2] [3] as you can see those self pro claimed DEX got hacked and suffer big losses.
Currently the real DEX until now is BISQ [4] they didn't hold any coins or money from customers account and you can use Tor network, this is what truly DEX it is.