The point is that you don't want to have anything on the music stand other than the music, because it has a tendency to fall off the music stand as soon as you turn the page. And if you could avoid having the music on the music stand as well, that'd be great, since then you don't need the page turns at all.

Smartwatch metronomes are also great in that they can tap you on the wrist instead of making an audible click. It's sometimes hard to hear the click if you're playing loud, and it limits their use to practice since you don't want anyone else hearing the click.