Britain, a victor that had never been occupied, wasn't able to lift many significant food rationing schemes until the 1950s. Bread, which wasn't rationed during the war, had to be rationed from '46 to '48.
There is a meaningful distinction between being the leading industrial power and being the overwhelmingly dominant economic power.
And this was despite having to ship all that stuff across an ocean.
The US was an industrial powerhouse then.
Post-WWII effects are one component. But another is that we want a protected shipbuilding industry for its own purposes, which is fine, but that curtails a lot of other production.
> What special capabilities could Us shipbuilders bring that would make the cost of labor here competitive with China or South Korea?
Energy. Our energy costs are much lower than theirs.
Whenever we're looking at the 1900s and wondering why the US used to be so dominant as an industrial power I think it's incredibly important to remember our industry got all the upside (an absolute torrent of money and demand) and none of the downside (bombing) of two world wars. IMO the US industrial base was riding high on that easily into the 80s and people mistake that dominance for skill and prowess rather than the waning boon of WW2's mobilization and destruction of every other extant industrial power.