What are you doing for community building: discord, FB groups, broadcast channels, or comments?

I'm torn between building a home base (discord/FB group/broadcast channels) vs just going all-in on comments where the attention already lives (reddit, IG, tiktok, YT). Home bases feel deeper but harder to start; comment-first feels faster but kind of rented land.

If you've actually built a community that talks without you forcing it, where did it happen and why? What was the first repeatable ritual like weekly thread, challenges, office hours, prompts? And what did you try that totally flopped?