Quantum entanglement "synchronizes state" faster than light, but cannot transmit information because that state is not able to be chosen, influenced, or controlled. It is read-only. The value is random, and read-only, but is guaranteed to be synchronized between both sides of the link, and that synchronization happens faster-than-light. So it's like a shared, random, read-only constant, whose state is the same everywhere despite lightspeed limits.
I realized that this could be utilized by people in multiple star systems to have a shared base of TV shows, movies, novels, video games, etc. that get distributed to everyone at the same time. (By "same time" I mean in the reference frame of our galaxy.) Here's the idea:
Well before we're able to send people to other stars, we'll almost certainly be able to use systems like GPT-3 to auto-generate TV shows, movies, novels, video game levels, and other works of fiction. My idea is to use quantum entangled particles to form a shared random seed that is the same at each star system. Each month, every planetary civilization should "open" the random seed for that month. At the same time, all the other planetary civilizations will open that month's seed as well. And they will all see the same value. That value will be used as the seed to generate that month's TV shows, movies, etc.
I fully understand that the quantum aspects here are superfluous. It would be completely possible for each month's random seed to just be hardcoded numbers specified in advance, and that would also be synchronized between all worlds. But where's the fun in that? I figure that people will still want novelty, and they will still want each month's TV shows and movies to feel new. If the seeds were all hardcoded in advance, they wouldn't have that novelty factor. By using quantum entanglement in the manner I describe, the TV shows and movies are truly created anew that very same month that they are released - and due to the synchronization scheme, everyone in the galaxy can view the same TV and movies that same month without lightspeed delays.
The Milky Way Galaxy is about 100,000 light-years across! At that size, it's not realistic to have real-time conversations. Even if we extend human lifespans to billions of years, communication will be more like email or snail mail than anything else. Having a scheme like the one I propose would allow for the real-time sharing of certain aspects of culture without these delays. If you have a buddy on the other side of the Galaxy, you can watch your favorite TV shows together on the same day, and you can picture their reactions when you see a joke you know they're laughing at. It's a way of being together even across the limits of time.