https://community.vancouvertech.com isn't very active now and its maintainer is considering shutting it down.
Kickstarter has been fronting the costs of running this instance. They're paying for a managed Discourse setup, about $120 per month.
Possibly the forum format isn't attractive to people who are used to Slack. Or maybe it didn't have sufficient network effect to take off.
When it first launched, I'd hoped Discourse would have been a safe place for thoughtful conversations. Whatever the reason, I'll be sad to see it go π―π