It will be as useful as other HN campaigns: stop using WhatsApp and use Signal, stop using Chrome and use Firefox, stop using Twitter and use this OSS alternative with 0.1% of the users, stop using Reddit, stop using Kubernetes, etc.
Maybe that’s changed. But a lot of folks don’t think so. Twitter is useful precisely due to its network effect. That’s why I’ll never move to mastodon. Doesn’t make sense for the reason that I use the tool.
This convenience-driven mindset extends to technical communities on Discord. Creating a server there is as simple as clicking a couple of buttons, whereas setting up a new forum requires significant technical effort and ongoing maintenance, besides $$$. These practical aspects are often overlooked in discussions, hence the failure of all these campaigns lead by a bit too technical people i.e. those who are willing to spend time researching alternatives and enduring their particular pains, and don't care about networking effects.
To challenge Discord effectively, create something equally convenient yet superior (like being indexable by Google). Wait for Discord's deep enshittification and seize the opportunity then. If it's not as convenient, don't expect users to switch. The average user won't invest time in learning new platforms when they can get everything faster and for free elsewhere.