In a world where American sitcoms, Yoga, Chinese manufactures and Coca-Cola have penetrated nearly everywhere, how much autonomy do traditional cultures still possess? Industry, economy, science and technology have been global now for many decades. The financial and intellectual elite have become cosmopolitan classes of their own. Vast population migrations have created exposed people from all over to cultures other than their own.
Nonetheless, cultures are things that don't easily loosen their grip. They are good at building walls. The most fundamental wall is probably language. 12,000 years ago, when there were 1000 times fewer people, these people probably spoke 10,000 different languages, each with 1000 or so speakers. today there are about the same number of languages, 6500 or so, but speakers are heavily concentrated in a few: Mandarin, Hindustani, English, Spanish, Arabic etc. Many of the smaller language groups are likely to disappear soon, but that will still leave thousands of languages, and perhaps, different cultures.
Nonetheless, a global superculture (super in the sense of being grafted onto the respective cultures of the members) is likely to persist, and likely to dominate business, technology, science, and aspects of art. At the moment, the native language of that group is English. For the future, TBD.