There are many reasons, from the cost of development to the security of the consensus algorithm. With AnyTrust Guarantee, Arbitrum will always execute a validator’s transaction if they are acting honestly, “even if all of the other validators are colluding to (try to) cheat”. Whereas many chains require a majority or two-thirds-honest assumptions, the AnyTrust
This means that users relinquish control over their private keys and rely on the security measures implemented by the exchange itself. While many centralized exchanges have robust security protocols in place, there is still a risk of hacking or theft. Crypto wallets are used for storing cryptocurrency, while an exchange is used for trading cryptocurrencies