Yeah, I pretty much only use reddit for a few game communities, unfortunately with this change I suspect more and more people will move to discord. It's pretty annoying, but I suspect I'll have to eventually cave and join them when they finally kill old.reddit.com.
IRC itself doesn't provide a shared history, threading etc.
You could get there with alternative clients and bots (at least if all participants use the same), but calling that IRC is a stretch
Oh boy, I can't wait to have to join a specific game discord for every game I want to play or else be locked out of any community information!
Discords are easily killing a lot of hobbies by sequestering away information. And even when you're told "Oh that answer is on XYZ discord" you have to go in and find the conversation using Discords ever-shittier search function