China hasn't seen 10% GDP growth for 15 years. It will likely fall in the 4-5% range this year as it was last year. China has a self-inflicted population decline problem that the U.S. doesn't, which will weigh on China's future growth prospects.
Are China's numbers accurate? They've clearly had huge growth over the past few decades but the economic statistics are heavily manipulated at all levels and the raw data is kept secret. Top-down external estimates generally put real growth rates a bit lower.