It's a little known fact, though, that despite some serious mistakes, the average economic growth through the Mao years was actually about the same as the later years. It's just, they started from such incredible rock bottom before the revolution that by the end of Mao it had just taken them from "everyone freakin' starving and bandits everywhere" to "poor".
A) caveat of trusting Communist GDP numbers, when there are many embedded incentives to lie
B) The "serious mistakes" include contraction of -27% in 1961, and the bigger loss of tens of millions of people starving to death
Apart from that, it's true that you could eyeball this graph https://data.worldbank.org/indicator/NY.GDP.MKTP.KD.ZG?locations=CN and conclude that the post-Leap average growth was the same. OTOH, it gets a lot smoother and more reliable after Deng's market-oriented reforms in 1979.
And some of the reforms started before 1979:
'In agrarian policy, the failures of food supply during the Great Leap were met by a gradual de-collectivization in the 1960s that foreshadowed further de-collectivization under Deng Xiaoping. Political scientist Meredith Jung-En Woo argues: "Unquestionably the regime failed to respond in time to save the lives of millions of peasants, but when it did respond, it ultimately transformed the livelihoods of several hundred million peasants (modestly in the early 1960s, but permanently after Deng Xiaoping's reforms subsequent to 1978)."'
And OTOH, a differently sourced graph shows post-reform GDP growth being much higher than before. https://en.wikipedia.org/wiki/Historical_GDP_of_China#/media/File:China's_real_GDP_growth_by_decade.svg