I love the simple elegance of the silhouette man. The figure can easily be constructed in PowerPoint by combining circles and rectangles and gives a lot of freedom to draw simple actions. Simple to draw, but the result does not look simplistic. If you find drawing them still to be a challenge, stock photo sites are full of ready-made files that you can use in your slides.
I recently designed a 150-page deck where he was used again and again in different situations. Here is an adaptation of one of the charts.