If you look at China, it's exactly due to the West's insatiable appetite for cheaper labor that it has become more technically competent, and more well-off, especially the coastal cities. And this is why it now (for some years) ceases to be a pool of cheap labor: the living standards, while not near Western, have risen so much, the Western customers started finding the labor cost too high. Now it's the turn of Vietnam for many industries.
Previous participants of this joyride: Japan, Korea, half of Southern Europe.
Reserves of cheap labor are not endless, and it's great that the capital actively seeks them out and eventually fills them in.
Let's not forget rampant corporate espionage, and deliberate IP infringement whereby designs used contractually to produce something, and then stolen to make knock offs as well.
In practice, in aggregate they are. As you mentioned, there were other countries filling that gap before, and there will be new ones. East Asia got there first because of a combination of factors (cultural, historic, and logistical), but once that area is spent, new frontiers will be opened. In fact, in markets where there are fewer logistical constraints (i.e. software), those new frontiers are already coming online (South America, Africa, etc).
Previous participants of this joyride: Japan, Korea, half of Southern Europe.
Reserves of cheap labor are not endless, and it's great that the capital actively seeks them out and eventually fills them in.