I think I see it, it seems to me that my finger naturally wants to hit in between "E" and "R", but it hits exactly on top of "I".

So ortho fixes this, but could it then introduce problems for other pairs? It seems hard to believe that there is a layout which is 100% better for all combinations.

Regarding symmetry, our hands are already asymmetrical due to handiness (left-handed, right-handed), and the brain naturally adapts, and there is also the risk of Hawthorne effect if you A/B test ortho/staggered. Some real studies on layouts would really be useful.