The security (e.g. passwords, 2FA, etc.) is roughly equivalent between Slack and Discord. In both cases you're hosting your messages on someone else's server.

The security (e.g. passwords, 2FA, etc.) is roughly equivalent between Slack and Discord. In both cases you're hosting your messages on someone else's server. For privacy, Discord has a bad track record, so as a business, I'd choose Slack over Discord. But I definitely prefer self-hosting communications infrastructure.