I came over to Discord in January 2016, from a combination of TS3, Forums & Skype for the purposes of both online and personal gaming groups. It decimated all the competition in gaming spaces for voice chat, async text chat and sync text chat within 6 months. Every single guild or group moved over almost overnight. That should go to show how absolutely revolutionary Discord was, and that it was an actual, huge software innovation. People _loved_ the UX & UI. Users loved the chat and channel interfaces, admins loved the fairly easy to understand moderation tools. Its gotten a little less loved as the app has gotten less and less reliable, the VoIP quality has been reduced (especially for non-nitro boosted servers) and new, unwanted features are added. However, I don't understand how the core UI is bad. Its not puke or emoji ridden beyond what users make of it -- avatars, server icons & banners, role colours, emojis in channel names etc are all user defined. Everything else (beyond the shitty new features they rollout for 6 months then kill) is pretty standard contemporary electron app design, and honestly minimalist in some ways. It is certainly minimalist and easier to navigate compared to something like Element.
I think that HN users seem to not fundamentally understand the needs of online groups beyond what is necessary to carry out an asynchronous open source engineering project. Much of the "bells-and-whistles" that discord offers are _essential_ to both the day-to-day communication of these groups as well as to moderators. Element does not come fully replicate some core features offering an outright less stable experience. Slack/Teams are not accessible to private users. Telegram has even less features than Element/Matrix.