As a non-American I can tell you how dead wrong this notion is. This might have been true in the mid-2000's when social media was still relatively new (and mostly Western). As it cascaded into other parts of the world, the novelty died off. In fact, to the contrary we are seeing more and more localization of content on social media and other digital platforms. A good example here is Tiktok in user generated content that has geographic & linguistic boundaries. Film, music & other sub-cultures have a much more powerful rubbing effect on pushing subtle American culture than SM.