There is a huge wave of transitions from reddit/ forums towards discord because it offers voice chat / image uploads for free. It's not gonna last at that, chat is a bad format compared to hierarchical replies, hard to search etc. Gaming is their niche but at some point games will want to stop bleeding their community to them. There is also a proliferation of communities which leads to a lot of activity because it's a new platform, but as always, very few of them will survive. Then at some point they 'll also block all NSFW content and more people will leave. The value of their offering is that they re free, but money runs out, and slack already exists. Another case of overfunding for unsustainable growth.