I tend to disagree. Charcoal was a massive industry before the industrial revolution, and people still managed to make a lot of boats. Thing is, the amount of labor it took to dig up a bunch of coal made it economical to burn it by the ton to run industrial processes - the amount of wood it would take to make the same amount of charcoal would take so much more labor to produce that I don't think it would ever be economical to burn charcoal for steam engines.