Recently I came across an article about the future of decentralized exchanges and how they are going to transform the centralized exchanges. One thing that clearly mentioned is that decentralized exchanges are secure and impossible (kind of) to hack as no central entity is running/controlling them. However, I heard about the security breach of Bancor and waves DEX. So what's the point of decentralized exchanges if they are still being hacked 
Maybe you haven't been around for too long but there have been a lot of exchange "hacking" from day one of bitcoin world, it all started with mt.gox and than moved to crypsty and so forth and now we are here where even the biggest exchange binance is keep getting attacks so its not really that much of an option anymore to have security against these hacks. When you have a decentralized exchange it means there is no self controlling mechanism that could benefit from a "hacking" situation, it could still get hacked literally but we will at least know that owners are not just saying hack and keeping the money, it must be really hacked. So all in all its just another layer of security put on top of all securities we had and that is why people prefer them over others.