I don’t those two thing are contradictory, it’s just that you are assuming you don’t get uniqueness inside a monopolistic platform, which is only partially true. The platform is fixed, but you get uniqueness inside the platform, with the content and contacts you follow. Facebook, reddit, etc. are not the same experience for all users. Comparing a network, where each vantage point is unique with Starbucks, which has maybe 50 products, is not an apt analogy.