People investing capital in superior production methods to more efficiently make items of higher demand creates wealth.
Capital mobility facilitates this, it means people and money are free to move where they receive the most gain.
Marx never considers that the value of things depends on demand, so every object that takes the same amount of labor to make is equally valuable under marxism. Gee why didn't that work.
Labor or Abstract labor?
Not quite accurate.
More like equal amounts of effort.
If two assemblers build two identical Chevies, and one builds his to Rolls Royce Standards in a week, and the other takes a month to meet Yugo standards, both must be considered equal, at least, or the Yugo must be sold for the price of a Rolls... since they were both intended to have value proportional to the effort expended..."
Remember the bread lines in the Soviet Union? Generations of them.
How hard is it to make bread?