Capital investment doesn’t just involve office buildings. It includes capital invested by others in the surrounding infrastructure. Good roads, rail systems, telecommunications, waste disposal, etc. ad infinitem.
Then there is the competitive advantage that comes from being in an area of high industrialization. If a factory in Detroit needs some new bearings , it can find a manufacturer locally, or use Fed-Ex to bring things in overnight. If a factory in Bangladesh needs a new bearing for a critical machine, it may be days to get a new one.
Then there’s political stability. No one in the U.S. worries about investing their billions and then losing the investment in a coup. 3rd world countries have immature governments. Not just the threat of coups, but of radical changes in the tax structure or regulation happen all the time.
But in the end, you’re right - capital is flowing into the 3rd world at a pretty good rate. This makes them more competitive. This is a good thing! Increasing wealth in the 3rd world raises world GDP, makes the world more stable, and most importantly, improves the lives of the people who need improvement the most.
And if enough capital gets invested there to make those people as productive as workers in the U.S., do you know what will happen? Their wages will rise.
Given free capital movement around the world, you will not wind up with the same wages everywhere. Rather, what you will find is that wages stabilize in a way that reflect the actual worker value in each country. Again, that’s a good thing. It’s moral and just. If someone can be productive, but you prevent them from making a living by using the force of government to stop people trading with them, you are acting immorally.
Free trade is economically efficient, raises the wealth of all people engaged in trade, and is the moral course of action.