Sure selecting a breed that was bred for a specific task sure does hedge in your favor. But to do a job well, you need to practice. 

Anyone can shoot a gun, but one puts in the work to be a sharp shooter.

Dogs are the same, of course genetics sure do help. But someone who wants a dog to retrieve teaches the dog the task. If you want a dog to do nosework, you teach them. Bitework, you aren't teaching them the action they know it. But you are teaching them when to and for how long as well as when to recall.