Mentoring and teaching others your accumulated technical expertise and business values increases your worth and positions you for future promotion.
Your ability to develop your subordinates so that they reach their maximum potential is one of the keys to career progress.
There are people in every company that others gravitate to because they give freely of their time, assisting their colleagues and less experienced people in solving problems, finding resources, or approaching situations from a new perspective based on practical experience and wise choices.
Superiors recognize these abilities and know that these key people whom others rally around and go to for advice and guidance represent future leaders who can be groomed for higher responsibilities.
Leading others forward often involves being of service to them.