In the future there will be billions of dollars stored in Wallets, what if one day they decide to stop and shut down their services and transfer all the money to their own wallet and confirm the transactions and convert all of their coins(Bitcoin and any other Altcoins) to USD and disappear?
How can we get our money back? whom can we sue? how can we prove how much coins we had in their wallet?
That means the exchange scams and there's no way to get our wallet back.
So, for more safety, you can use decentralized exchange such as IDEX or other for safety