FoxConn alone employs 1.2 million people, almost all of them in assembly. I guess they are paid to watch the machines.
the place I work for doesnt even have a percentage of that kind of workforce, and is jam packed with all sorts of very nice equipment, one thing I have noticed is that no matter how awesome it is ... it screws up
so you have a crew running around adjusting and tinkering, and you have a 24/7 workforce feeding the machines parts, double checking quality, unloading machines, packaging, moving panels for different stages etc. just cause its mostly automated doesn't mean there is no use for people.
as far as resistors go, we use 1% parts, and it allows us to build pretty consistent products though millions of that product. for example I used 5% parts in a couple manual test rigs back in the lab to mirror one of our automated units, theres a +100mV on one compared to the tester out in production, the other is -100mV (rounding here btw) both of which are out of our tolerances for the part
... guess what I get to do next week