Comment by dwaite

All three of those products launched with custom hardware made by partnered manufacturers.

At iPhone launch, I seem to remember Apple still having quite a bit of the flash ram market tied up from their exclusive iPod contracts - Apple basically helped finance new factories to be spun up in return for exclusive access to their production.

The Apple Watch had the S1 system on package, which included an Apple custom CPU. There were a number of miniaturization techniques and custom parts Apple used which I remember competitors lagging on being able to replicate due to the broader market tendency to integrate off the shelf products (but I don't have more part examples or timelines).

Since they try to stay secretive about upcoming products, competitors may only get hints about what Apple is doing through your typical industrial espionage channels until the product comes out. That creates quite a bit of lag then you are starting a new product design cycle based on a product your competitor just hit the market with.