This suggests that the immediate availability of a drop-in replacement today means there is no utility in encouraging that growth.
There are multiple open-source tools that do everything Discord does. There are few-to-none that offer everything Discord does, and certainly none that are centralized, network-effect-capture-ready.
Short term:
* Small group chats with known friends: Signal, whatsapp, IRC, Matrix
* Community chat: Zulip, Rocket.chat
* Community voice: Mumble, Teamspeak
* Video / screen sharing and voice chat: Zoom, BigBlueButton, Jitsi
I've heard about Stoat but haven't read up on it.
None of those play in the same league as discord for hosting a community, and none of them look in a position to be there in the foreseeable future. It sucks but that's how it is.