A cold piece of knowledge. The U.S. didn't actually give China much time. China really only got 3 years.
in 2001 China joined the World Trade Organization, in 2002 China was closed because of the SARS epidemic. in 2006, the US re-imposed massive sanctions on China under the pretext of dumping. So, in fact, the only time China really got normal treatment was in 2003, 2004 and 2005.
China's growth rates for those three years were 11.5%, 12.7%, and 14.2%. In these three years China has rapidly completed the reform of state-owned enterprises, turning all these loss-making enterprises into powerful conglomerates. In these three years, China's foreign exchange reserves have risen from $280 billion to $1.1 trillion, and it has completely gotten rid of its debt crisis.
So it's not that the Americans were stupid enough to give China too much time. Rather, it is that the Chinese government is far more efficient and capable than normal people can imagine.