Some exchanges listed there as top may have never been hacked yet but you can never use any of them confidently. They probably upgrade their security every now and then but they remain as a target for hackers. They are all centralized exchanges and they are like sitting ducks waiting to be shot.
Everyone should check out decentralized exchanges or P2P trading platforms.
absolutely p2p escrow exchanges are far better in terms of security , most of these exchanges mentioned are vulnerable and prone to hackers