You're being heavily downvoted because this instance is "a community of free software and privacy enthusiasts" as the title on the front page suggests, and this in particular is the !opensource@lemmy.ml community. Discord is the complete antithesis of this, as it is a proprietary application locked to a centralized server that also spies on its users.
That being said, there are modern alternatives to IRC, such as Matrix, XMPP, Zulip, Mattermost, or RocketChat. However, I think IRC is fairly good at what it does.