Mao was broadly successful. Trading 5% of abundant population for superstructure of modern Chinese state that subsequent leadership snowballed into what PRC is today is frankly a bargin. You don't get modern PRC state capacity without Mao speedrunning industrialization and cultural heterogeneity. Nation building on scale of PRC from the shit state post war China is hard. He didn't ace it, but vs developing peers post war that spluttered, or the other billion+ country with more favourable starting conditions, grading on a curve, Mao gets top marks, especially when PRC was playing on extra hard mode with US containment.