My suspicion when reading about twentieth century Chinese history is that a key goal, for all the factions, was to remove the economic stranglehold the Europeans had gained over China due to being first movers with the industrial revolution. Once it was clear that Mao's ideas were not strengthening the economy, they would have tried Deng's ideas or something similar.
However, though I think the crazier ideas of Mao would have been dropped, they could have tried a functional but poor and egalitarian economy, isolation from the rest of the world, and pouring what resources they had into a defensive oriented military (no attempts to project power over the Spratleys). They would have eventually reconciled with Russia like IOTL since that makes sense for balance of power reasons. This is sort of what Cuba wound up as, a poor country but functional and still independent of the USA and still communist.
This would actually be a huge boon to the world biosphere, and also help working people in Western countries. Without the world essentially shifting its industrial production to China you get more jobs in other places and much less carbon emissions. Chinese economic expansion also had distorting effects on various resource rich developing nations.
One question I have is whether they still try to control their over-population problem (also due to crazy Maoist policies). That was an undercredited factor in post 1975 Chinese economic success.
I don't think the Vietnames Doi Moi reforms happen without the Chinese example.