DEX still has a long way to go to beat current top centralized exchanges. Yes, DEX did improve a lot in 2019 (remember the shitty etherdelta lol) but DEX still lacks behind in few things which can only be provided by CEX.
But we have seen the potential DEX to be a trend in 2020, a countless project is created based on DEX and some of them keep improving it until now giving a unique and friendly feeling to the users. It might not be able to bear centralized exchanges right now but nobody can say anything about the future, even those top exchanges are creating their own DEX because of this. DEX is we need to complete the meaning of peer to peer transactions.