Evolution will be imported wherever engineering balks. Synthetic evolution technology is already employed in the frontier formerly called bioengineering. Here's a real-world problem. You need a drug to combat a disease whose mechanism has just been isolated. Think of the mechanism as a lock.
Organic molecules are immensely complex.
They consist of thousands of atoms that can be arranged in billions of ways. Simply knowing the chemical ingredients of a protein does not tell us much about its structure. Folding a protein is similar to the task of pushing a mile-long stretch of string marked in blue at six points, and trying to fold the string up into a bundle so that the six points of blue all land on different outside faces of the bundle. There are uncountable ways you could proceed, of which only a very few would work. And usually you wouldn't know which sequence was even close until you had completed most of it.