Re: this is true
The importance of mediators is underrated. Fred Brooks (in Man-Month) highlights the essential role of leaders with broad knowledge and experience. Only with their help will there be fruitful communication between systems and people that do not communicate well unmediated.
Mediators will be very powerful, and my experience is that the tops of the hierarchy only rarely tolerate them.
A related question: How is it possible to recruit the right people, and how can their competences be maintained? I have no answer.