They can't. That's the reason why they have been leaving in droves, but it's very hush hush so far. A lot of microelectronics assembly has already moved out of the country. Samsung and Sony, for example, are closing all of their smartphone manufacturing operations in China.
Most foreign companies that chose to manufacture in China didn't make that decision to acquire access to the local market. Even if that turned out to be lagniappe. They chose it for cheap manufacturing and export.
Even among first tier brands, a lot of products/designs/parts come completely externally sourced.
Flagship, image making products like Apple Iphones are made with some level of in-house involvement, but even they were cookie cutter products based on Samsung reference design up until 3gs.
I myself once worked for a company doing sourcing for a company that did sourcing for Amazon when they were just started venturing into hardware with Kindel. Any such project is at least 50% external input, otherwise they simply don't have an ability to pull it out for the lack of hands on industry expertise.
> Find me the American that doesn't have a Chinese-made TV, a Chinese-made phone, a Chinese-made laptop...
American living in Europe here, and while I realize this is a bit of a curveball I'd like to point out that it is not difficult to avoid Chinese made products. My TV is a Samsung made in Hungary, my phone made in Taiwan (I do have an old Thinkpad made in China though).
I try to avoid Chinese made products. Not because of any nationalism, but because better quality alternatives exist at nearly the same price point.
For example I have a German made fridge and it's exceptional. It is difficult to get excited about a fridge but when I disassemble the shelves and bins to clean it I notice carefully finished edges beneath cosmetic covers that most customers would never see. The plastic parts haven't gone brittle and do not crack or chip. The glass shelves are thick and heavy and tempered. There are thoughtful touches that come from superior engineering and quality raw materials. It only cost a tiny bit more than similar Chinese models and I expect it will outlast them while retaining all of its original functionality.
As an American living in America, I find it fascinating that one of the few things I agree with Trump supporters in my area about is that we should avoid Chinese goods as much as possible.
Now it's for two different reasons - theirs is because of nationalism, mine is because of build quality.
But as an example, Pony woodworking clamps used to be made in Chicago, they shut down manufacturing 15 or so years ago, and recently started remaking clamps. Remaking them in China at the world's largest clamp manufacturer. The quality is not comparable. The older, Chicago made clamps, some of mine are from the 70's, are still good to use every day. I bought a handful of the new clamps to try them out, and the finish just isn't there. They're just shoddy compared to the older versions. I certainly don't see them lasting 40-50 years with constant use.
Samsung and Sony exports massively from their Chinese plants.
Also, the smartphone market in China is shrinking. That's the reason for the current scramble for marketshare outside China. The market has reached saturation and the major Chinese brands are growing only at the expense of the smaller ones disappearing.
