Someone has to ship the products (including warehousing). Someone has to sell the products (store fronts/web masters). People can get away from unskilled labor and go into things like... building/repairing robots. (Relatively low learning curve. My father has gone through a couple training classes on repair/upkeep. They are about as easy to replace parts as computers are today and/or changing the brakes on a car.) Someone has to program the robots. Someone has to clean and upkeep the factory floor (equipment). We've been moving more and more to a service industry (arts, entertainment, cosmetology, waiter/waitress, sales, computer information[yeah, I don't consider this manufacturing], construction[repair/upkeep]...) opposed to actually producing items. That's not a bad thing, but it hedges on people actually spending money on these things. If people feel overtaxed or unsure of the country at any point, that quickly sees a downturn in spending because people start saving.
Of course, this all should be obvious, but I thought I'd re-iterate. A production based economy maybe more stable (because need/demand is pretty constant for some things...), but you run into the issues you've been discussing. Eventually, third world manufacturing is going to cost more and more and hopefully stabilize, but it takes time. So we have to do the best with what we can do internally, adapt and take on more responsibility: learn new skills, adjust to demand, seek to find ways to reduce labor needs to keep manufacturing here [and create maintenance jobs] and cross train people to more than menial tasks. Today's jobs can not be as simple as inserting Part A in Socket A a thousand times a day. Sadly, some people (and companies) would like to simplify every job to that point (which isn't "bad") so you're going to have to adapt with the company and find a suitable replacement position.