The amount of market power Apple has left even after such extensive regulation still far surpasses what a small company can hope to get by building even the mos

The amount of market power Apple has left even after such extensive regulation still far surpasses what a small company can hope to get by building even the most restricted walled garden. So, if there were any medium companies just below the regulation threshold, the discontinuity argument would make sense. But there isn't, and there won't be, precisely because of anti-competitive behavior of the giants, they can sustain walled gardens precisely because they are giants.