software can keep traveling groups together
you do bring up interesting point about families and children.
surely, a software tweak could be made, in which everyone within the same reservation number would be kept together in the same boarding number.
in fact, the software could even prioritise family boarding by making them first before others get to board.
that is the way most airlines and amtrak do it at large terminals - passengers with small children or with disabilities get to board first, since they need a head start to get going down the boarding area, and then others follow afterwards in the boarding queue.