The hardware business is...
Let's just say that the difficulties you face definitely exist for hardware engineers.
But, difficulties involving negotiations plus recalcitrant South Korean factory owners are WORSE.
In "South Korean factory owner negotiations," secrecy is paramount.
Particularly if said South Korean factory owner is the biggest supplier of iPhone screens. And also makes an entire line of competitor phones to your products.
Apple's CEO, COO and "head of services" all have degrees from Duke University and 30 year careers in supply chain management. The company is widely regarded as being run by a Gang of 4, those 3 plus the general counsel.
From the outside, Apple is very much a hardware company that knows nothing about software.
The software is only good because Mac fans join the company and slave hard enough to make it that way.