The Author's intent of Black Mirror is to show the externalities of technology., focusing on the effects of social media. This now applies to systems such as China's social credit system that was recently developed. Nosedive is a critique of social media and the extent it goes to is when social media runs your life. It shows its place when a society values kindness and politeness. This comes to the detraction of lacking actual happiness and inauthentic social interaction. The director imagines a world of people reviewing each other, "much like Uber." The directors mentions that he is not a big advocate for social media, and we see that reflected in a satirical story. He did not like how people are constantly comparing themselves to others.
Interview with Joe Wright: https://www.hollywoodreporter.com/video/bryce-dallas-howard-joe-wright-928000