Ask yourself why the USSR was unable to compete with the US economically, and could not even feed itself (Kansas in the 1970s was known as "the breadbasket of the Soviet Union". Why the Chinese could not compete with the US until they switched to free labor. Why N. Korea is starving and regular shipments of food from the west keeps things from getting much worse. The Middle East is not known for exporting factory goods.

The examples go on and on.

Where forced labor still exists there is something else propping it up or subsidizing it - like I mentioned with prison labor.

Claiming that labor in the USSR was slave labor is disingenuous and quite a stretch. By the same standard, I can claim that Western wage labor was also slave labor.

I'm also dubious of your Kansas claims (Google search comes up with nothing). Again, by the same standard, I can claim that the US "cannot even clothe itself" today. I'm sure reality is a lot more nuanced than that.

I can expand further on history of the USSR and long-term effects of WW2 on that country's population, which had massive waves of effect well into 1990s, but I'll stop here.