I've used Riot as a Slack replacement and setup notification bots. Its effective for the task and I could use the IRC bridge for a similar function.

Only reason I moved over to Discord was too many chat apps and the hobby users were all on Discord anyway.

Riot has inline Markdown, so I'd argue it's actually superior to Slack for serious work.

Riot is more slack-like than whatsapp-like. We use it at work instead of Slack now.