@Gustavo, Co-Moderator posted:
I understand the clause starting with "diminishing" to be a reduced which-clause functioning as a sentence modifier. The subject of "diminishing" is "the fact that automation's focus on enhancing speed and efficiency often has the effect of removing complexity from jobs." This is what diminishes the challenge jobs present and the engagement they promote.
Thank you for your support as always, Gustavo. Are there any effective clues to differentiate the function of 'ing' in such uneasy cases as above?