Fineness aside, the main quality you want in your ground coffee is a very even size distribution around your desired size. If a lot of the resulting grinds are smaller or larger, especially very fine dust, the resulting brew will be much less balanced. If you want to, you can buy a sifter set to sort out different particle sizes. If you really want to, there’s software to do optical size distribution analysis.

Exactly this. That’s why I installed an aftermarket exhaust when I did it on a previous car