when deleting in insert mode, why don't dynamics shift too?

Just curious: if I select an entire bar of every part, and delete the contents with insert mode on, it dutifully moves all the music, including lyrics, articulations, playing markings, text, etc.

…except dynamics, which stay where they were entered.

I’m curious why this is the case, and if there is better way to remove a bar or a beat than selecting and deleting in insert mode?

It might work better to select the bar and invoke the bars popover (shift-b) and -1
Or split flows before and after the bar, delete the middle flow and merge the twothat remain.

By default, dynamics are not entered into a specific voice, but rather they apply to all voices on the staff. When you remove material in Insert mode, at the moment only material that is actually in the voice you’re working in will be shifted.