When you seriously come to think about it - storing your Crypto in exchanges is better than using cold wallets.
Looks like you was booze-fueled when wrote that. Say that face-to-face to customers who experienced disasters of Mt.Gox-grade. Cold wallets under personal control are the safest places where private keys for crypto can be stored, hardware wallets follow. Exchanges must be considered as the spots for trading and/or conversion rather than for storing.
Truth to be told many people are so used to the fiat system in which you let a bank store and protect your coins that despite this whole market being built under the premise of being your own bank people want to go back to the old model and it is obvious centralized institutions like exchanges are happy to perform that function, that is why exchanges which technically should be a place to just exchange your coins have become banks de facto.
And this is very troubling because as we know exchanges are hacked all the time and once you lose your coins in this market there is no way to get them back and while some argue the exchange will cover the losses that is only true if they are at fault, if you are hacked because of your own mistakes then those coins are gone.