For me, it's looking at how people respond to a changing world. While the show is careful not to include specific historical events, each character has a role to play society's reaction to that change. Some are at the lead, some are making the transition, and some are clinging to the old ways.
Meanwhile, all of these people, with many different points of view, are trying to manage a single company that must be able to accurately reflect popular culture to survive.
The show is a slow burn, but the advantage of that is you get to get a long stare at each person involved. They don't rush through personal transitions, and none of them feel unnatural.