A decentralized exchange is better than a centralized exchange obviously. The fact that every other site in the world needs you to use some personal information to access it just makes it a farm for data collection which is obviously going to be sold to the darknet. Every centralized exchange is like that and you may not able to keep all your information secret if you use a centralized one. There have been some decentralized exchanges but they are still in process of development and gaining popularity.