Copper is not gold, and, even if billions of iPhones with copper coils in them are made, the cost per will be small; Apple will inflate the cost per just because it can.
The copper is not going to be diverted from other (essential) use, just more of the existing stock used by Apple. There is no global shortage of copper, unlike cobalt, and its price is at the lower end of the 52-week price, and about 60% of what it was about a decade ago.
An aside note, from what I have seen of housing construction in the last two decades, builders are going cheap by using plastic based pipes for water pipes small and large, saving anywhere between $200-500 per house. A nice thing to note with mining stocks still in the dumps.