I think I’m going to put it back into a wall and leave it for someone else to find in 50 years.

Found in the walls while remodeling my basement.

Simple answer. Any transference of energy is going to have losses. How would you create steam? By burning fossil fuels of course. So now you burn the fuel, create stream, use steam to generate electricity, use electricity to power ship. That’s two extra steps and potential loss of energy as opposed to just directly powering the ship by burning fuel. More energy lost means less efficient. Less efficient means more fuel burnt. Burning more fuel costs more money.