Why i think Decentralized Exchange need in our future ?

1.Centralized exchange hacking risk
Centralized exchanges are easy to use, easy to access and they provide advanced trading functionalities like margin trading and others. However, they also represent a security risk for your funds. While some exchanges are better guarded than others, hacks are not an uncommon event in the cryptocurrency scene, and some like the recent Bitfinex hack have led thousands of users losing their savings.

2.Benefits
The most obvious benefit to using a decentralized exchange over a centralized one is their "trustless" nature. You are not required to trust the security or honesty of the exchange since the funds are held by you in your personal wallet and not by a third party.

Another advantage to the decentralized model is the privacy it provides. Users are not required to disclose their personal details to anyone, except if the exchange method involves bank transfers, in which case your identity is revealed only to the person that is selling or buying from you.

Furthermore, the hosting of decentralized exchanges is distributed through nodes meaning that there is no risk of server downtime.

But still need more development
Even though Decentralized Exchange have many benefits, still need more development in a future. Because of some downsides. Some decentralized exchanges like Bitsquare require users to be online in order for an order to be listed and for the trade to take place, requiring users to perform certain actions like signaling that a payment was received.
Trading features like margin trading, lending and stop loss are currently not available in the decentralized model as they only allow the basic exchange of currency for a predetermined value.

Here is some Decentralized Exchange :

bisq.network
Bisq is an open-source desktop application that allows you to buy and sell bitcoins in exchange for national currencies, or alternative crypto currencies.

wallet.bitshares.org
Bitshares has a way of always slipping under the radar, but this platform has the best daily volume that has been around $6 million as of late. This asset exchange is a place to trade with both asset-pegged and fiat-pegged tokens.

openledger.io
Openledger is where you can trade a decent number of different cryptos. The daily volume on Openledger is around $3million.

counterparty.io
Counterparty is a decentralized exchange that uses the Bitcoin blockchain and the Counterparty protocol acts as a decentralized escrow service.