Discord for Chatting instead of Mattermost

Hello, since the most threads here are really old (mostly a few years) I wanted to ask if the project is still being active and in active development.
Also may consider making a Discord https://discord.com for active talking instead of using Mattermost that all people can join it without requiring to contact staff via Email for joining.

Have answered the question myself by looking onto the source codes of the applications, but discord should be really considered as it’s an really good platform for chatting.

But discord is not open-sources, and they does not respect at all their users, bots devs and others.
I really hate the company behind Discord for what they do. I rally prefer a more privacy friendly alternative. Maybe not mattermost because you need to email an admin. But something like an open rocket.chat instance or a revolt.chat server/guild.