Just because I (and they, obviously ;-)) don't know a legitimate reason to use modulinos and the like

Though modulinos are too sneaky/clever for my tastes ("scripts should use modules, not pretend to be modules"), they do have some well-respected fans, led by their illustrious inventor brian_d_foy, as described in more detail at modulino References.

My preference is keep my script mainlines as short as is practicable, with all the heavy lifting done in (unit-tested) module/s.

👁️🍾👍🦟