China has been suppressing domestic private consumption, it stands at just 40% of the GDP. For comparison, the US is at 68% and Germany is at 53%.
This was probably done to prevent the appearance of the true middle class. China has no problem controlling a fairly small percentage of rich people, but the Party is afraid of large population strata that might start asking for political representation.
But it does give them a _lot_ of leeway for easy growth. They just need to make the country more business-friendly at the lower end.