One pretty good barrier that Apple has built and defends well is the phone as a status symbol and object of desire.
But, as a phone, I think low end disruptors are here, and I can't understand why people would pay 3 or 4 times as much as needed for a phone - other than that they have the money, and they want the phones for reasons unrelated to performance (aesthetics, perceived quality, privacy, etc.).
Xiaomi in particular is trying to erode that particular Apple barrier, their flagships are already objects of desire in India, China and in my country (Uruguay).
