Do they though? In most of those scenes 99% of the audience is other, less-famous starlets who want to improve their status by being seen in connection <big shot name in the respective industry>. They don't care at all about what the big shot is actually doing or saying.

Huh? You must have some other case in mind.

The audience for "celebrity gossip" is billions of people. The audience for fashion (and related magazines) too. And the audience for influencers is tons of people who are not influencers and rarely any "less-famous starlets".