So why dosen't America have a shipbuilding industry that can do it?
The Jones Act also screws over Alaska, by the way.
The Simple answer is "Money".
More complex, it is that everything ended up more expensive than elsewhere. That and unions.
Ship builders were/are unionized and therefore expensive and lazy(less productive) compared to workers in the orient. Steel workers, and ships use a lot of steel, same deal. Cheaper to build where you can get cheaper steel AND cheaper workers. US safety and environmental regulations aren't necessarily bad, but still increase expense.
We retain some building capacity because of the Act, but it also allowed builders to get lazy. So not only are our labor costs higher today, we have less automation available, so not only is our labor more expensive today, as well as components, building a ship domestically requires more labor.
And really, I understand the desire to retain the ability to build ships domestically, but I don't see a good way to fix the problems so that we're even within 10% of competitive.