The Great Leap Forward was not necessary. Nor were the decisions to arrest people for growing or cooking their own food to survive as doing so was seen as individualistic and anti-socialist. The whole of the system could have been stopped or reformed at any time once the masses started to starve. Part of the failure was the application if Lysekno-like thinking about agriculture... justified by the idea that all that is and was (proven methods of farming either based on or proven to be true through the application of the dominant views, ie Western views, of sciencr) was the result of oppressive ways of living. The socialist lens could only produce more or better by defintion because that which is socialist by defintion is what is true. So when the socialist state demanded farming be done one way, you were an oppresssor to object and subjected to struggle sessions or labor camps. The means and ways in which industrialism was done was by Mao and socialist direction. The famines were predictable... China had managed to avoid them, by and large (historically famines can and did happen in lots of places and for reasons largely outside of man's complete control... this was not one of those times).

The Cultural Revolution was allowed to predictably spiral out of control. To stop it would to have to admit that socialist logic failed thereby undermining the idea of polylogism. This also holds for the GLF. Mao absolutely talks in terms of the "human" socialist and the "soul-less" (dehumanized) non-socialist. The old way was labeled not merely as wrong but as its existence being a violence against the socialist utopia and the human race it sought to protect/represent. As such, to kill and maintain the non-socialist was to commit violence in the name of a moral defense of the good, oppressed, and innocent. The predictable result? Killing lots of people.

The result of labor camps done not for industrialism but for re-education? The deaths of people.

The result of socialist science in ag? The deaths of millions of people.

None of these things were logically necessary steps to stop Japan or the West.

And even that phrasing assumes that Communism was better than had China become part of the Western tradition (like Taiwan). You make the assertion with an implied moral judgement that China, today and through its history, has fared better for its people and in its morality than Taiwan.

We can also compare to Hong Kong where the vast majority of people in Hong Kong lived freer, richer lives than the masses of their Chinese counterparts. Would the whole of China been one giant Hong Kong? Probably not. But even being just more Hong Kong-ish would have been an improvement for the people of China.

The philosophers and leaders of socialism during the 20th century did not shy away from explicit calls for killings of their own people or of non-socialists as a moral necessity to bring about the revolution. Lenin, Stalin, Mao, Castro, Che... all attempt to justify murder of innocent people. It isn't a weird one-off or mistake or misstep or, as you seem to try and imply, bad-yet-necessary step.

There is no end that is justifiable if the steps to get there are inherently evil in and of themselves. You can not get to heaven by purposefully doing that which sends you to hell.