Look at animated movies. They're giant collaborations of hundreds of mostly anonymous people, basically large software development projects. They hire stars to do the voices, not because they're all that great as voice actors (trained voice actors can often be had cheaper), but to be the face of the film in public and promote it.
That is, the skill of a Hollywood star is not really anything to do with the product, but simply being famous, recognizable, and likeable. They are a brand, like Mickey Mouse or Colonel Sanders (once an actual person!).
One of the sanctions the SEC seeks for repeat offenders is a ban on serving as an officer of any public company.