Decentralized Exchanges and the protocols that they are built upon have seen huge strides being made in the last couple of years. A lot of issues that a general purpose blockchain use-case faces like scalability, slow-adoption, volatility and whatnot are gradually fading away.
Most of these problems stem from the fact that a large number of claiming-to-be Decentralized exchanges were either hidden behind centralized back-end systems
Decentralized exchanges appear more and more every day. They appear for the reason that people have a need to trade crypto. But this doesn't mean that centralized exchanges will become decentralized. No one wants to lose control of them. Decentralization is the absence of control.