Not who you're asking, but Bisq seems like the closest thing to a truly decentralized exchange right now:
How Bisq resists censorship
Bisqs network is a fully distributed P2P network, and thus difficult to shut down
Bisqs network is built on top of Tor, and thus inherits Tors own censorship resistance
Bisq is code, not a company; it is not incorporated, and it cannot be disincorporated
If nothing else, like Bitcoin, it has no single point of failure unlike EtherDelta.
I think Bisq is great, but it's never going to overtake traditional exchanges. It's strictly P2P -- no automatic orders, no order books. It's really inefficient for price discovery. It's basically a distributed LocalBitcoins.
What we need are decentralized websites, file storage and communications protocols for everything currently run on local servers. I wonder how feasible that is...