The entire starting point of this article is flawed. US-China rapprochement under Nixon in 1971-72 grew out of geopolitical calculations, not economic or trade. Remember the Cold War and the Vietnam War?
For the US, the rapprochement promised to help it extricate itself from the Vietnam War, on the view that Beijing had significant influence in Hanoi, and it also would serve to split the communist bloc, then led by the Soviet Union.
For China, the rapprochement would end its isolation, and help it to counter the Soviet Union diplomatically. China-Soviet relations were very poor at that point, and a war had nearly erupted between the two communist giants after border clashes in 1969.
During the 1970s through 1980s, both the US and China saw the USSR as a common foe. In fact, the CIA even had monitoring stations in China targeted at the Soviet Union.
The point is that US-China relations grew in the 1970s and 1980s during the Cold War because it served both their geopolitical interests. At this stage however, it is clear that those interests have diverged. That is the nature of geopolitics.