One of the reasons farmers have always crossbred animals or plants of different varieties is heterosis, the tendency for the resulting offspring to be better than either of its parents in some way.
Heterosis, also known as hybrid vigor, is a key factor in modern agriculture and animal breeding. Perhaps a crossbred plant can withstand drought better, or maybe it bears more fruit per plant. Maybe a crossbred animal is stronger and can pull heavier loads, or perhaps it doesn't get sick as easily. Crossbreeding is how we've produced more resilient varieties of wheat, and it's how we got the popular Labradoodle dog, which has a low-shedding coat (and a high adorability factor).