Like xmas/santa, the most fitting age for enjoying the cute aspect of these events should be around 15yo or below. Being older, accompanying children for assisting with their enjoyment of the event would be more natural, I presume.
Attending or organizing parties would be more befitting of young adults, certainly (leaving aside some candy for the eventuality of any trick-or-treaters of course).
Attending or organizing parties would be more befitting of young adults, certainly (leaving aside some candy for the eventuality of any trick-or-treaters of course).