The US isn’t doing what China is accused of because they lack the ability. They definitely would if all corporations were state controlled.

Snowden documents clearly show the US corporations cooperate with NSA by providing backdoors. We don't know for sure if they do this because they are being forced to, bribed, or just nice to the government agencies, but the end effect is the same: they do whatever the US agencies tell them to.

It shows they turn over information it does not show they do the bidding of the US government. There is a legal process in the US that must be abided by while this isn’t true of the PRC. The line between corporation and state is a blurry one in China, to say the least.

Installing backdoors isn't "turning over information". And I'm not sure secret cangaroo courts match the typical western understanding of the term "legal process".