I think "less capable moderation tools" is really underselling how purposefully useless and nonexistent Slack's moderation tools are for open communities. I cannot overstate how terrible Slack is in this regard.

To be clear, I really and truly don't fault them for this: Slack's always been clear that their focus is on business communication, which is a totally different animal when it comes to moderation needs. Discord is nearly infinitely better in the sense that they have any tooling at all, but it's still considerably far behind the resources I've got when moderating a large Discourse instance.