So I want to ask another question. If there is a decentralized exchange: user friendly and easy to use. How can it prove that is it really decentralized? How can you say that 'okay this is really decentralized and I am secure here.'?
Are you blockchain developer? If not, how can believe a person to this?
Take a look at NebliDex. It is open source and anyone can verify the code logic of how the exchange works.