Since, as von Clausewitz said, war is a continuation of politics by other means it's meaningless to discuss a war while ignoring politics. In practical terms if China invades it's a near certainty that the USA would immediately enter on the side of Taiwan, and quite likely that Japan (at least) would be drawn in. RUSI estimates from 100 simulations that in 99 cases the USA wins but loses two or three supercarriers and 35,000 troops. The losses to China would even more catastrophic. It's hard to predict the exact impact on the economy of Japan but it would be serious, perhaps dire. China would be sanctioned out the wazoo and would suffer economic collapse that would hobble them for a couple generations, possibly creating a regime change. The American people would not be thrilled with losing $15B worth of hardware and 10% of our naval personal creating some political challenges for whoever happens to hold the WH at the time. The world economy would take a huge hit, the ability of the USA to project power around the world would be greatly diminished and Russia would be in a much stronger position.

There wouldn't be plastic bowls for $.50 at Walmart for a while but that would be the least of anyone's worries!