If their only value prop was cheap labour then manufacturing could easily have flourished in plenty of other countries with cheap labour (eastern europe, latin america, africa?). And plenty are geographically closer and have more similar language/culture to the western markets than Asia. But there is more to it, Asian countries have a talent for it and have mastered manufacturing and related industries like steel production.
I doubt any American factories could legitimately compete with Asia, even if the wages were the same, without some heavy-duty automation. And Asia has many other advantages around vertical integration of factories, such as access to raw materials, from there and other countries they've developed relationships with.
Now it's possible these advantages are just a side-effect of the fact the industry residing in Asia in recent decades but I believe there's far more to it, even regardless of the wage advantages, they are very much deserving of that industry.
If you look holistically at what happened, you're more likely to find why so much moved to Asia. Geographically speaking there may have been closer low-wage countries, but distance alone does not determine where you can build appropriate facilities.
Geologically, China has access to large ports, allowing large amounts of tonnage to flow in and out. You have a generally easy path from China to California. Eastern Europe is out because you can't easily ship to and from. Similarly, jungles and mountains in Latin/South America and Africa keep large manufacturing bases from being built. Africa lacks sufficient ports - its largest ships 1/10 the tonnage that Shanghai does.
At a local political level, you have governments willing to subsidize manufacturing and tolerate certain working conditions that other governments wouldn't. From an international perspective, you have incentives to bring capitalism to the borders of previous socialist countries as a destabilization measure (large increases in US-China trade in the 80s).
Yes, people in other countries are people too, etc., but they also have their own governance, their own resources, their own economics systems to manage and oversee.
I can take no active part in any of that--only my own country's.
Until we have one world government, I'm always going to prioritize the places where I have at least some capacity to pull the levers in ways I think are better for people.
(This is why I dislike, in general, the specious globalist argument, "but the poors overseas deserve wealth too," sure they do, but they also live in sovereign nations and it's up to them to guide and shape their own.)
And that I find to be a shame -- that we find it so difficult to see the logic in a position we may disagree with.
The other thing is, I don't just apply this to international politics, I'm a firm believer in working to change your local politics as much as possible above all else.
How your city runs is both more accessible to the layperson and has a far bigger impact on your day-to-day experience than federal stuff, for example.
That's not to say I'd eschew federal level politics--I'm a huge proponent for socialized medicine, stringent environmental regulations, and a host of other stuff.
But when I go out and campaign, I do it for local folks.