There was a picture going around o reddit of 50 totally different varieties of potatoes grown in Peru. How many varieties do we grow that are significantly distinct? This is probably caused by the optimization of industrial farming selecting for best yield (kg) with very little regard for looks, taste, or even nutricion. It's also harder to stock supermarkets with 50 different types of potatoes, carrots, lettuces, and dozens of other vegetables. Maybe a solution could be that not all supermarkets sell everything, instead of all of them selling exactly the same selection of products. But this would be too inconvenient and would never be tolerated.