Rita Fainshtein makes waffles:
Why is it more challenging to get an accurate answer from pie/donut charts and why do we feel less confident trying to read them?
The main reason is the difficulty in calculating the areas of the pie slices/lengths of the donut arcs.
This is much more challenging and less confident than comparing the areas of rectangular shapes.
Rita takes a look at the waffle chart custom visual available for Power BI and then builds something custom fit for the task.