You have it backwards. Manufacturing iPhones is much easier than designing iPhones. Apple can manufacture somewhere else, but China can't Apple somewhere else.
The context of this conversation is the root level comment noting a Bloomberg article where it's stated it would take them 8 years to move 10% of their manufacturing capacity to other countries from China.
Now, it still may be true that it's easier to manufacture iPhones than design them, but easier does not mean easy. Personally, I think you're just vastly underestimating how hard it is to manufacture iPhones at scale, which means not just finding the right part, but a part that can be delivered in the quantity and quality required to meet their production needs, and repeated for all the parts they need.
Patents are worthwhile only as far as they are respected. A factory is a real asset employing many real people.
Anyway, why does SV have a lock on design? If anything computer design has gotten very stale since the early 90s when all the competitors to American computer systems finally croaked