As a newer in trading I choose to use exchange which is less fees and at the same time with have good liquidity. But some of the good exchanges that has a good liquidity of transactions has a huge fees needed so it is optional for everyone to pick their best exchange.
That's certainly true, mate. We must consider the fees and liquidity of a DEX before we conduct our trades in it. Recently, DEXs have become popular (although not at the same level of centralized exchanges). If people recognize that their privacy and security is at risk within centralized exchanges, then they'll switch over to DEXs (which contributes towards the increase of liquidity over time). AFAIK, IDEX is one of the fastest and most responsive decentralized exchanges out there. There are lots of tokens listed there, and with the Wings partnership, things will become even better over time.
On the other hand, there's another DEX which has an interesting concept. It's called MoonDEX and it provides hefty rewards to those who can afford a masternode. Based on Bitshares' Graphene technology, MoonDEX will be able to process large TPS without delays or downtime. The masternodes feature is quite interesting, as it will allow you to earn MDEX coins passively, while using them as a discount for fees within the exchange. Cryptobridge by the way, is also a good DEX and it provides a reward system to holders of Bridgecoin (BCO).
This all means that DEXs are creating attractive revenue models, that are sure to attract people into them. Once they've gathered many users, they could probably replace centralized exchanges if they could maintain a high level of performance. Nonetheless, in the future, DEXs might take over if they experience adoption within the mainstream world. The best DEXs out there are: IDEX, EtherDelta, ForkDelta, Bitshares/OpenLedger, MoonDEX, CryptoBridge, Switcheo, Bancor, Saturn.Network, 0x, Radar Relay, and even Altcoin.io. Just my opinion