Not sure about a-listers. Most of them try to look young.
why do you need influencers?
Basically because 1) if you ask someone on the street to describe what Forever Labs is, they can't, and 2) people in general require external validation before doing something new. From what I understand, that's why everyone is crazy about influencers, macro-influencers, micro-influencers, etc. We are all trying to sell you something. Well, I am not. Aside from storing your stem cells, and the Wayfarers Roleplaying Game, and Hubski I suppose. But that's me selling my stuff. Which I think is cool. That's why I do it.