I think you're missing the point. Presentations are no different than giving a speech with visual aids, with the additional benefit of sharing your notes after the fact. You can give a sales pitch, a conference talk, an internal update, or share some info about your favorite band. Its free form and incredibly versatile. Analytics isn't going to replace a conference talk, or a sales pitch.

That's not to mention the wide variety of uses for Excel. It's everything from a financial analysis tool to a digital scratch paper.

Slack is fine but it's just a slow irc client with pretty good search.