In large part because it seems like just about every other OSS project is on Discord these days, and Discord makes it very easy to see all your servers at once

In large part because it seems like just about every other OSS project is on Discord these days, and Discord makes it very easy to see all your servers at once and switch between them seamlessly. We're already seeing more activity even with only some users having migrated so far (it's only been a week for us). I looked into options a while back, and had also considered Matrix which seemed to fit with open-source a lot better, but it had a relative lack of features and momentum compared to Discord. Zulip seems more like Slack, and since we liked Discord's approach and feature set too, Zulip wasn't that appealing.