Why the first large steel experiment was a cargo ship

Why was the first large steel ship built as a cargo carrier?

A cargo ship tested large-scale steel construction without risking a warship program if the experiment failed.

A cargo carrier offered a practical test bed for large-scale steel construction. Builders could verify the material and construction method without accepting the military risk of experimenting first on a warship. The choice separated an industrial trial from the higher consequences of losing a combat vessel or discovering serious defects after naval investment.