Purism already do this.

So does Apple with the Mac Pro and a ton of historical pre-Intel Macs.

But not with phones.

Yes bc iPhones are a much more global product than MacBooks.

They don't do it with the MacBooks either, just Mac Pros.

MacBooks don’t exist anymore

Literally every single Laptop Apple sells is branded as “MacBook”. Its really adds nothing to point out someone didn’t add the word “Pro” or “Air”.

I was using your terminology.

Is that why Librem 5s cost 10x other phones with similar hardware?

This is why Librem 5 USA costs $2k. Original Librem 5 costs a lot for other reasons: https://news.ycombinator.com/item?id=21656355.

Curious how many dollars it would add to each iPhone.

That depends. The US is really cheap if your factory is fully automated, and Apple makes enough phones that full automation seems like it should be a win. For smaller production runs cheap labor is cheaper than the cost of building automation. Optimizing these curves is hard. (Note that China is really a lot cost of labor country anymore, and so production is moving away, but this is a long slow process, not to mention China is investing in automation and reportedly doing well)