Progress on decentralized exchanges has been very disappointing after all the hype they generated last year. The real-time order matching and liquidity of centralized exchanges is far superior. I have no idea when that'll change for the better. When I need to quickly enter or exit a trade, a DEX is never that attractive.

Another thing: Most or all of the current DEXs are only quasi-decentralized. You may be the sole holder of your private keys, but trading requires the use of trusted third parties -- servers, domains, etc. For example, Etherdelta was hacked by attackers who replaced its DNS registry. The attackers were able to phish any private keys imported by traders while the site was hijacked.