The US, Japan, China, India and Europe all watch the same major block buster movies. We can talk to each other about the MCU and at least have some idea what each other is talking about. There are only a hand full of religions left in the world unless you want to counter obscure ones and each sect and even then three of those big ones are basically branches of the same religion. the most common language in the world is spoken by a large variety of people all over the planet while the second is pretty regional.

An advanced society would probably end up being monocultured going by the one model we have. Though it could depend on if they are a space fairing race and how long it takes to travel between 'settlements.'