It's all about the quality of interpersonal relationships.
Leadership is a liberal art—Peter Drucker's assertion. ("Management science" is an oxymoron.)
Listening ("fierce listening," as one wag puts it) is arguably/inarguably leadership "Tool #1." (Training in listening should be intense/rigorous/universal.)
"Authenticity" only goes so far—e.g., leaders aren't allowed to have bad days, especially on bad days.
At the end of the day (one's professional life), one remembers the people one has helped—net worth never goes on the tombstone.
"Leadership" is an 18-year-old working at McDonald's who brings a great attitude to work on a gloomy day. (E.g., per Betsy Myers's Take the Lead, every hour offers up leadership opportunities to every one of us.
The tools (e.g., social media) may be new, but the basics of leading—"It's the people, stupid!"—are eternal.