This video should help you understand article 210.4 a,b,c,d about multiwire branch circuits.
The main reason for the code would be to help protect service personal while working on the circuits.
Another reason to pull in separate neutrals vs using a common trip handle is that when rewiring a building it certainly helpful to have the extra neutral.
Pay close attention when laying out your home runs for wire fill because the neutral is considered a current carrying conductor.Be sure to count it.
The NEC code requires that the wiring be identified
at least 1 point in the originating panel.