So better have ship building capacity at 0% of China's and it be impossible to buy US built ships at any cost?
In a vacuum, the Jones Act should be encouraging the construction of new shipyards and/or freight rail infrastructure. That neither seems to have happened suggests that other barriers exist, and those barriers need addressed, Jones Act or no.
Let alone - merchant ships are needed to trade and interact with allies in these extreme situations. And last I checked Maersk is a Danish company, and Danmark is a close ally.
I agree that the Jones Act sucks, but I do think there's some valid reason behind trying to do what it tried to do.
As it stands - merchant fleet of US allied nations is strong enough for US to not need one at all.