Poverty is defined as lacking basic needs, and while Mao-era China was still relatively underdeveloped, the people were not poor because they got basic needs met.

I'm glad to see I'm not the only one here who is suspicious of the metrics used to prop up the 800 million lifted out of poverty narrative. IIRC the data used to justify the claim is a World Bank report that shows the population making over a certain threshold of income increasing. As you touched on, this data says nothing as to whether or not their needs are actually met.