It’s centralized, closed source SaaS, it’s not an open, standardised internet protocol with a vast selection of clients (and servers, real servers!) to choose from.
10 years from now, Discord will be gone but IRC will remain.
These days I prefer Matrix, but I have no doubt IRC will stay around. Maybe even because of Matrix users like myself who just keep bridging it in.
"Remaining" is a pretty weak consolation. Is that all that matters? The biggest Freenode channel I'm a part of is #nodejs. It has maybe 10 regulars. All of us probably 30+ years old, only clinging to the corpse of IRC out of old habit. And in 10 years we will all be 40+, and in another 10, we will all be 50+.
On the other hand, in 10 years if Discord pulls the plug, you'll have a community of people that can migrate elsewhere. To any other solution that will pop up. Because it's the people that are the community, not the platform. Whether I have to use Discord or Slack or future solutions is merely incidental and entirely swappable.
One example that comes to mind is https://thedonald.win/. Reddit killed their subreddit (r/the_donald), so they just moved elsewhere.
10 years from now, Discord will be gone but IRC will remain.
These days I prefer Matrix, but I have no doubt IRC will stay around. Maybe even because of Matrix users like myself who just keep bridging it in.