Discord shines when you use it with a tight-knit group. A RL friend group, a gaming clan, etc.
But there are a ton of these big public servers that are essentially just spam, because that's what happens when you collect a load of random people in one place who have one minor interest in common at best, and then try and get them to hang out socially.
It's a group chat app, not a forum. And being thrown into a group chat with 100 strangers is kind of the worst.