My dog refuses to eat dry food

Hello. I am in a pickle. Many years ago, my wife decided to add people food on top of my dogs’ dry food. Since then, they will never eat dry food alone. Now, my dogs are getting a bit older, but still picky. However, I believe the people food isn’t sitting well any longer…is there any hope to my dogs eating dry food alone??? And is there any reason to add wet food toppers in lieu of the people food?? Help! My wife is a little blinded by the dogs puppy eyes!