How do early start ups build a community?

What are people using to grow early startup communities now? I keep seeing the same pattern: founders launch a product, open a Discord or Slack, invite users in, and then the community goes quiet after the first few days. The hard part does not seem to be creating the server. It is giving people a real reason to come back, ask questions, share progress, or help each other without the founder forcing every conversation. Curious what has actually worked for you: small private groups with high-signal users, public Discord servers, newsletters that push people back into the community, founder-led office hours, product updates and feedback loops or something else What is the best way to grow a community around an early product without it becoming another dead chat room?