The rest of the world was in total shambles until 1960s. Europe was destroyed by two world wars. East Asia was an economic backwaters. Same was true about most of South America, and its advanced regions were underpopulated compared to US. Africa was and is Africa. There was simply no other place that could build stuff at scale.

This article covers a lot of the history. https://www.noahpinion.blog/p/why-cant-the-us-build-ships

Basically the US wasn’t great at shipbuilding post civil war due to high costs. WWII was an existential threat so cost was no object, and we coasted on that capacity for a long time.

Thanks for the link. That article doesn't really support the GP's contention that the Jones Act is the root cause of the U.S.' shipbuilding failures.

Increasing wages and the service economy.

For other high income nations the ship building industry has specialized on higher tech vessels while leaving the enormous labor intensive container ships to South Korea and now lately China.