Hypercard was very much a presentation software. It had the best animations at the time, compared to Powerpoint. And it supported features that seem obvious once you hear about them: from any slide (card), you could click on an element of the slide, and it would take you to another slide about that element. Powerpoint is still mostly focused on linear "next slide" all the time.

In other words, with Powerpoint, you are presenting to a passive audience. With Hypercard, you were handing the control of the presentation to the attendee, and they could drive the presentation wherever they wanted.