why does "moving/duplicating above/below staff" destroy the voice structure?

Why does “moving/duplicating above/below staff” destroy the voice structure?
The multiple voices are combined after applying “move/duplicate above/below staff”.
Is it intended?

If you want to cross a note to the staff above or below without changing the voice it’s in, use N/M (Edit > Cross Staff > Cross to Staff Above/Below) rather than moving or duplicating the notes to the staff above or below.

Moving/duplicating to the staff above or below basically automates cutting the note from the original staff, then pasting into the new staff, so it uses the first voice on the destination staff, just like regular pasting does. This is absolutely as intended.

Thank you for the kind explanation!

Would it not make more sense for the action to paste to the first n voices in the destination staff depending on the number of voices selected in the original staff? I can get the desired result by using reduce instead of copy, but this requires multiple steps.