Because it’s still not Markdown, not by a long shot. https://api.slack.com/reference/surfaces/formatting#basics https://api.slack.com/reference/surfaces/formatt

Because it’s still not Markdown, not by a long shot. https://api.slack.com/reference/surfaces/formatting#basics https://api.slack.com/reference/surfaces/formatting#basics may call it “mrkdwn”, but it bears only a very superficial resemblance to Markdown—in significant chunks it’s closer to one or two other lightweight markup languages than to Markdown.