The article argues that forums are a better choice than Slack or Discord for supporting developer communities due to their ability to preserve knowledge and provide a searchable archive of discussions. The author highlights several problems with using chat platforms, including the 'memory hole' where valuable information is lost, and the difficulty of searching and accessing historical conversations. The article suggests that forums are more suitable for building a knowledge base and providing long-term support. The author's experience with building a developer community using a forum is cited as an example of the effectiveness of this approach.