This is exactly the policy the US seeks to now reverse (absorbing over-capacity) and which planned reversal China meets with threats of war. It wasn't charity as you well understand. The US exported its inefficient industries initially for the unfulfilled expectation of access to much greater markets for its efficient industries.
How charitable of them.
Well, whatever makes one sleep at night with their national superiority intact.
As a third party that's neither Chinese nor American, that's what I see.