My understanding is that Mao believes peasants are the true revolutionary spirits in China given that it was an agrarian society & they are exploited by landlords. Meanwhile, Marx was different - he believed peasants were people that were forced off the land by capitalists which then turned into proletariats. And so in the Marxism context, it's the industrial workers are a good revolutionary source vs the capitalists. Marx termed the idea of surplus labor, which obvs is flawed because he didn't take into the context of the risks that the capitalists have to take. In other words, I think it is used as a positive context and to show also the transformation of also Chinese society from Mao period to now, which is more urban than rural and the term peasants no long apply to modern Chinese society with urbanization rate about 67% in 2024.