That 1.4 Billion peaked 15 years ago - according to the latest Chinese Census. Population will drop to 700 million by 2050 - 28 years from now.
Chinese labor costs have jumped 12 fold over the last 20 years. They will never be the low cost producer of anything ever again. (that is not subsidized)
That 1.4 billion was China's 2021 population report of their 2020 census.
Some of their most pessimistic internal estimates predict a population of 700 million by 2050, but the UN projection is for a population of approximately 1.1 billion in 2100.
So, who are you gonna believe?