Actually, I deal with a failure of American agriculture. Were it a "success story" as opposed to a mythology, we would at least be able to feed ourselves as a nation. Yet since 2000, this country has run a negative balance of payments in agricultural products for human consumption.
Again, why is native habitat better.
Nobody knows because there isn't any that truly is. Somebody had to do that research and we are farther along than anyone else in the country. There are PhDs that have traveled a thousand miles just to see it. What I can tell you is that although we have increased our count of vascular plants to 363 species (from 60), our soils were virtually destroyed by the apple farm that this once was.
Show me the figures. The US has 90 million cattle, 60 million hogs, more than a billion poultry, 75 million acres of beans 35% of which is exported! and 90 million acres of corn with record yields. We are 5% of the worlds population but are responsible for 15% of the global food supply. Is there a country that produces more food? Obesity is the #1 health issue and we didn’t get that way eating air sandwiches.
You are right that there is no evidence that native is necessarily better. How many of the vascular plants you mentioned are food sources? 1000s of native plants are poisonous because they have been at war with herbivores for eons.