Comment by ceeplusplus

Their strategy uniquely gives you the upside of internal R&D (pace, funding, and direction are set by you) with none of the downside (potential disruption by new technologies). Apple can drop a supplier on a dime if a disruptive technology comes out. If that same tech was being developed in house, there would have been too much internal politics and momentum for that switch to happen. But because they bankroll capex, they have control over the direction and pace of incremental R&D.