"Core to editing is cropping" sounds very weird to me. As similar a counter-thought I could say core to taking good photos is not needing to crop. But I understand it's good leave some leeway sometimes.Editing has become much easier and ubiquitous, even encouraged with apps. And core to editing is cropping. The more data, the better. Printing is pretty far down the list of how images are used or shared now. That output makes up a share of use likely inconsequential to sales.
That print size thing was just an example of the difference. Isn't that size dependant on the pixel amount? So anyway we are talking about the size that 20MP gives compared to 24MP. It's not big difference at all.
24MP APS-C is 6000x4000 pixels vs 20MP M43 which is 5184x3888 pixels. 816x112 pixels more.