That's a bit pessimistic. China transformed from an agrarian backwater into -by some measures- the most powerful country on Earth, in the span of thirty years. I don't see why the Congo couldn't do something similar.
I feel like there's a pretty tremendous difference though- China had a long prior history of being the most powerful country on earth and the Congo has no such past. Not to mention that the example is quite possibly an outlier rather than the general trend of what's possible for most nations.