> why isn't the west's own supply chain options as immense?

They used to be. Since roughly the 80's, policymakers have decided it is better for the shareholders to outsource most of that industry overseas to China and India and etc, where the labor is cheaper.

Note that workers and especially union members actually have every incentive to keep that production domestic, but shareholders and CEOs profit when they can cut labor costs and the typical Western consumer values cheap products more than the health of domestic industry.

Western industries have been supported by subsidies, tax incentives, bailouts, low interest rates, and a dozen other things from the gov't but the same policies reward outsourcing and financial engineering more than actual production capacity.