The establishment of an exchange must obtain permission and this is done so that the exchange can operate and sometimes the owner or person who has shares in it plays dirty games such as money laundering. But not all exchanges do that and if the exchange wants to look bigger, maybe the founders and people who own shares in it will try to play clean so that their exchange can progress and develop.

I don't think it's good behavior to use an exchange to store the bitcoin assets we have because as far as I know there are many exchanges that end up having problems. The exchange is used by most people only for trading and transaction matters because the rest we will move assets to a wallet which is much safer and more secure.