If we grow only natives, this would be mostly true. Seeds are from all over the world. We have to manipulate to become more like the origin of the seed. Hybrids, I believe, are developed to over come these difficulties. I'm pretty sure even open pollinated seed, does not resemble exact original specimen.But lets face it most of us are doing way more than what is necessary. These are plants that will grow in nature with or without us manipulating the earth. They may not produce as much, be as healthy and may fall victim to pests or disease but at the end of the day they often find a way to survive.
Grow vegetables meant for your climate, it makes life easier.