The Logitech is conformed to the shape of the human hand ; which is what ergonomics is suppose to be. The scroll controls on a M720 ( and other Logitech mice) are right where normal people's index and middle fingers lie when normally grasping the device. Putting controls where your fingers are anyway is 'ergonomics'.
Perhaps someone with amputated index finger the Magic mouse is somewhat more adaptive of that non-normal hand configuration. But that really doesn't make it more ergonomic. Missing multiple fingers the MM will be about as ungainly to move as the other mice.
The MM is a bit more ambidextrous , but that is largely at loosing ergonomic fit so equally mis adjusted for both left and right handed folks ( 100% of population ). As opposed to missing approximately 10% ( or having to make two products; right and left hand versions. ). That is a trade-off with more ergonomic for 90% and somewhat worse for 10% (if don't do the second product). Apple worse for 100% isn't 'more' ergonomic.
The MM isn't really about 'scrolling' on multiple points. It is more about putting a mini track-pad on the top of the mouse., The multiple points thing is just a small effect (not an ergonomic primary objective). It is Apple's skew toward macOS being primarily aimed at laptops (with trackpads) and trying to promote the unique trackpad gestures and the associated 'muscle memory' (so 'annoyed' when it isn't there... hence buy Apple's more expensive alternative).
The other Apple objective is 'button-less' ... which really isn't necessarily an ergonomic improvement. (e.g, Apple Displays with no buttons. )