Everyone hosting their own Ventrilo/Mumble/Ts3 servers had the huge advantage that not only one single company got all data everyone produces. Not to mention outages.
They say in the blog post
> Routing all your network traffic through Discord servers also ensures that your IP address is never leaked
Yeah, except to your centralized company servers.
> Supporting large group channels (we have seen 1000 people taking turns speaking) requires client-server networking architecture because peer-to-peer networking becomes prohibitively expensive as the number of participants increases.
It's unfortunate, but it's just the truth. The reason we aren't seeing decentralized solutions to the problem that Discord solves is technical. It's not because people don't want it or aren't trying. I just doesn't perform well enough.
Not many selfhosted (eg decentralized) solutions use peer2peer because this requires NAT punching and other methods. TS3, Mumble and Ventrilo are all "proxies" in that manner and not peer to peer
> Yeah, except to your centralized company servers.
Which most gamers don't care about.
What they do care about, is what follows that sentence: "preventing anyone from finding out your IP address and launching a DDoS attack against you".
Especially for high profile e-sports figures and streamers, that's a very real problem: they want to interact with their fans using chat/voice calls, without giving bad actors the means to DDoS their residential connections (causing disconnects from game matches etc).
That's also why Discord proxies all embedded media from third parties through their own servers (except for some major sites, that are white-listed).