At the very least discord doesn't make threads which get lost in the channel like slack. But both suffer without tools like telegram which automatically catalogs all links, files, images, etc into tabs. But at the end of the day a chat system isn't meant to be documentation. It's meant to be chat. If you and me talk in the hallway, we wouldn't then tell a colleague oh yeah we figured it out in the hallway don't worry. We would try and document it somehow so that it's useful later.
“We figured it out in the hallway, go play back the recording from the hallway recording system until you find the bit where we addressed it”
Discord does have threads, just that they are so heavy weight and even less discoverable that they don't get much use.
Glad to hear I’m not the only one. It makes me irrationally angry when I see Discord being the support channel for a product.
What next.js does is pretty neat. They have discord but they have a bot that mirrors all the help threads onto a public website so that it can be indexed by search engines