I don't think that's what the person I replied to had in mind-- I think they were picturing this being a jobs program for the US with lots of American's doing the assembly and other American's happily paying more for their phones because nationalism.
Oh, you and I are on the same page. I think they see the number of jobs generated in China for iPhone manufacturing and think that translates to being able to have an equivalent number of jobs here in the US. I've been trying to make the point that they don't comprehend how enormous of an undertaking that would be - having to build basically a gigantic Apple city - to do it the same way as it's being done in China, and how you are actually going to have a lot of trouble getting
hundreds of thousands of people to relocate to this new densely packed Apple city. I think they're making a whole bunch of promises they can't keep, on the part of all these supposed workers about what hoops they'll jump through in order to get a 40 hour a week factory job in a brand new town, sitting at a work bench doing very high precision detail work assembling phones for 8 hours a day, then going home to live in housing that's one step removed from company dormitories. I think in reality you wouldn't be able to get
many hundreds of thousands of Americans to sign up for that. A quick search suggested Foxconn has around 350k workers in Shenzhen. The person we've been responding to suggested 3 shifts of 300k each would be a good idea in the US. With spares, management, etc., that's in the neighborhood of a million factory workers. In one densely packed city. All working at the same plant doing the same thing. I don't think there's a snowball's chance in hell of that actually happening - not because Apple doesn't have the wherewithal to build it, but because you won't get a
million Americans to relocate there to do that work. So, yeah, automation is the future.
Setting up multiple plants around the world makes Apple more resilient against price fluctuations (eh, imbalances in currency exchange rates between regions and such), things "going excitingly wrong" in specific areas (again, if China were to heavily damage Taiwan in an invasion attempt next week/month/year, Apple would be screwed, or, say, "covid-23" causes China to shut down Shenzhen again), and, as you say, protectionism. IIRC, that's the main reason Apple has a factory in Brazil, and one of the reasons they're setting up manufacturing in India. I don't know that they need dozens of factories, but a handful scattered around the globe makes them more resilient in the long run, and Apple is better than most companies at playing the long game. I think the overhead of more technicians is offset by the other advantages. Plus, you know, the cost savings from not having to pay a million Americans to do detailed assembly work 24/7.