Having an awesome website is like paying once for an employee that never stops working. An employee that can act as the face of your business, provide information without needing to talk to a human and even generate sales! On the flip side, having a bad website is like paying for an employee that doesn't come in to work at all. Basically a waste of money.
In theory this makes a lot of sense, but not everything can be as simple in the real world! A high-quality website needs one crucial thing to actually show results: traffic! If no one visits your website, then it can only be as good as a bad one.