It is a highly profitable business.. I don't know anything about construction, but generally speaking founding a startup in a historically profitable industry

It is a highly profitable business.. I don't know anything about construction, but generally speaking founding a startup in a historically profitable industry means that there's a lot of room for competitors to counter if you try to disrupt the industry (eg they can afford to invest and improve, they're just not bothering because they don't need to), and it's hard to win on price because competitors aren't particularly cost conscious as they don't need to be. If you want an easier time when you found a startup look for an industry with potential to grow. Then you can focus on growing the market rather than trying to compete for customers. Customer acquisition is far harder, and far more expensive, if you're trying to take market share from other businesses. The smart move is to go where no one has gone yet.