Not even close.
Opening our factories, research universities and defense facilities to Chinese workers was far more damaging.
From a geo-strategic standpoint, I agree, but the genie is out of the bottle. In my view, there's nothing we could have done to stop the juggernaut. Once they decided to return to some form of market economy (as has been prevalent for most of China's history), it was simply a matter of time before they caught up, economically-speaking.
Prior to the 1911 revolution that ended the monarchy, China's backwater status probably had its roots in its falling behind in technology after the West's Industrial Revolution and a combination of feckless economic policies ranging from corrupt imperial monopolies (aka crony capitalism) and capricious economic interventions having to do with smashing up concentrations of wealth. During the first 30 years of Communist rule after 1949's victory over the Nationalists, they compounded the capricious and destructive legacies of monarchical rule with the capricious and destructive policies of a centrally-planned economy. The 1979 liberalization ended the misbegotten Marxist economic policies that had brought China, in relative terms, to almost last place on the planet in terms of GDP per capita, a point it had never reached in thousands of years under the rule of absolute monarchs. The result, in economic terms, was a rocket ride that continues today.