The US gains very substantial economic benefits from being an attractive place for international companies to do business. Foreign investors know that when they invest in America, they're getting a stable regulatory environment and a reasonably trustworthy civil legal system. If America decides to undermine that trust for short-term gain, there will be a substantial long-term cost.
You might believe that hostile trade policies prevent American companies from competing in the Chinese market, but that's starkly contradicted by the number of American companies for whom China is a key market. Apple earn $11bn a year in China. Wal-Mart have thousands of stores there. Yum! Brands (KFC, Pizza Hut and Taco Bell) have 40% of the Chinese fast food market and make more revenue there than anywhere else. Starbucks have 70% of the Chinese coffee market. The shelves of Chinese convenience stores are groaning with American-owned brands.
An all-out trade war with China might be appealing, but be under no illusions that it'll be all upside for America. If China want to put the hurt on America, they have more levers to pull and more staying power. It's definitely not a fight you want to lose, but it might not even be a fight worth winning.
China aren't thinking about next quarter or next year, they're thinking about the next generation. Where does the US see itself in 2050?