Any nation with a large rural population with access to easy credit has the potential for massive growth.
The majority of China's population still consists of subsistence farmers. China should be able to maintain rapid growth until those farmers are integrated into a modern industrialized economy at which point the returns on investment will start to diminish like it has for every other industrialized nation.
China can't integrate those farmers, there are no jobs for them. And that's before China has to lay off tens of millions of industrial workers they no longer need, and that's before robotics completely decimates low-value manufacturing.
Those subsistence farmers are kept that way because there's nothing else for them to do and there never will be. China can't allow the productivity of their farming to rise - it's among the lowest on earth - because of the social chaos that would occur. Unless you can find another three to four billion global consumers equal to your typical US or European consumer, such that China can then employ 450 million more people in jobs.
The majority of China's population still consists of subsistence farmers. China should be able to maintain rapid growth until those farmers are integrated into a modern industrialized economy at which point the returns on investment will start to diminish like it has for every other industrialized nation.