What makes a Discord community worth staying in?

I’m Mahi, one of the makers of OpenBoxComm. We run focused Discord servers for developers, gamers and students, and I keep wondering why some communities stay active while most go quiet after a month.

For you, what made a community stick? Was it the people, the moderation, the topic, the events? And what made you leave one?

I’m curious about experiences from any community, not just ours. I’ll reply to everyone.