I definitely agree with you here, I like split ortho a lot (I'm typing this on an ergodox) but I'm super doubtful of any benefit for non-split orthos. My arms don't sprout from the center of my chest!
I actually prefer non-split orthos but with a split layout. What
I mean with that is something similar to split keyboards but
angled and within one case. This is still very ergonomic but
more portable. Combined with columnar stagger and reduced to
about 42 keys I find it extremely comfortable to type on.
Oh yeah, when I say non-split I mean fully rectangular layouts where the left and right hands are perfectly parallel. If you have clearly separated left and right sides that counts as split for me, even if they're within the same case.
That being said obviously you have more flexibility if you have fully separated sides, but it does tend to make the keyboard harder to carry around.