A live demo is orders of magnitude more compelling than a video.

When it's a video you're just watching it from a distance, not having to pay attention.

You're not dealt in.

You might watch it at 2x speed, or while you're distracted by something else.

When it's a live demo, you can't fast forward.

To not be rude, you give it your full attention.

You are dealt in.

Similar to the experience of watching a scary movie with your kid, vs thinking about whether a movie you've seen before would be scary for your kid.