Yup - Slack is geared for teams, and Discord is geared for groups. Discord has much better moderation tools - permissions, roles, etc; Discord makes it easy to run a server strangers can join. Slack has virtually no moderation tools at all, and even at the paid tiers, it's weak. Slack is a very poor choice for anything but a tight-knit top-down administrated group, where moderation can happen outside the app itself.