Decentralization. Anyone can run their own node of the software making it resistant to censorship, malicious control by the devs themselves or a third party.

Augur.casino runs their own node of Augur but runs it on IPFS, allowing others to connect to it.

Provides convenience if a user doesn't care about decentralization.

Just btw, I'm not affiliated with augur or augur.casino or any of these projects. I just find them interesting