That's the problem. It would be way more and people looking to get a bargain would haggle over that 10% (plus something) anyway.

Also, Apple gets a lot of its revenue outside the US. China is actually a really big market for them. It about rivals Europe. North + South America is about 40% of the revenue for Apple. A lot of that would be from the US; but not all of it. Let's call it 30%. Made in the US just doesn't have a whole lot of appeal outside of the US and Apple has the rest of the world to worry about as well.

There is one, but you're going to pay more than 10% more.

https://puri.sm/products/librem-5-usa/

Problem is it wouldn’t be 10% more, it’d be 100% more