Mosaic plots: responsive, flexbox-based parts-to-whole visualizations

I understand there have been studies showing people don't estimate angles as well as linear distances but people go too far out of their way to avoid pie charts when parts within whole data is shown. The 1D mosaic plot is effectively a stacked bar chart but there I suspect there is also some bias given toward the largest component such that the relative proportions of the smaller components are not well discriminated.

This is a neat and natural idea. I'm actually sort of surprised I haven't seen something like this before. It's one of those things that you think "oh I could have thought of that," but then nobody does until now :)