“The car needs servicing.” You are more likely to get the car serviced if the advice came from your regular mechanic instead of a friend who borrowed the car for a day.
Leaders often rely on advice from a close group of advisors.
Brands pay big money to ‘influencers’ or ‘brand ambassadors’ to promote products and services to their followers.
Messenger matters. To the same degree as the message. Often more.
The right messenger has a combination of status, experience, network of followers and knows the best language to communicate in.