Take a look at this chart:
Japan and South Korea are major industrial and manufacturing players.
The goal of the US is to derail China's economic ascension by pulling it into a war with US proxies in the Pacific region, while the US supports them from behind. In order to do that, the US must be able to convince its vassals that they must fight China, and the only way that will happen is if China attacks those countries first. The American plan is then to goad China into launching AR against Taiwan, and then support TW from bases in Philippines, Japan, South Korea, and Australia. China would then have to either attack those aforementioned countries, or allow TW to be resupplied indefinitely. Either way, the US would be able to achieve its objective.
From the US perspective, they do not believe TW would get steamrolled. They believe that TW will be able to hold out long enough for the above scenario to play out.