The “ortholinear” design is no closer to human hand shape than the standard row-stagger keyboard layout is. Both are in my opinion terrible, designed using poorly chosen criteria/constraints (in the case of the standard keyboard, not poorly chosen originally, but now a century out of date). “Ortholinear” just piles uniqueness on top, losing the >100 year historical legacy the standard keyboard has. The only advantages “ortholinear” has over the standard design are (1) symmetry, which might make it slightly easier to transfer knowledge about hand motions between right and left hands (I think this is a marginal advantage at best), and (2) whatever aesthetic benefit you think there is to a strict grid. This is not a functional advantage, but some people have strong aesthetic preferences, so it can’t be entirely dismissed.
If you examine human finger motions and human hand shape, and start the hand in some initial “home” position on the keyboard, and then try to reason about how difficult various keys should be to press various keys, it’s easy to conclude that some keys will be marginally harder to press in an “ortholinear” scheme, and other keys will be marginally easier to press. If you are willing to also adopt a keyboard layout explicitly designed for the difficulty of pressing various keys in strict grid layout, you can probably do better than QWERTY. However, it would be equally possible to design a better logical letter assignment given the standard keyboard shape. The best designs in either case are only marginally different.
Specific “ortholinear” keyboards might be better than specific “standard” keyboards, if they have e.g. more hand separation, easier to reach modifier keys (the TypeMatrix falls into these categories), more thumb keys, or a more portable size. The same design features could easily be added to an otherwise standard keyboard though.
To get to a truly better design, it’s necessary to scrap preconceptions about proper keyboard shape, and place keys where they’re easiest for real human fingers to get to. If building a keyboard with two flat halves, this results in a column-oriented stagger. If you can construct a board with a more 3d design, this design principle results in varying heights between columns and rows, so that e.g. the middle finger keys are vertically lower than the pinky keys.