I never had an issue with food in America. I bought at Wholefoods and at Trader Joes. Yes, if you went to Krogers anx the supermarkets, but in 11 years, I never shopped there.
My point is that there was choice. I have had no choice in Germany, Portugal, Ireland, and previously in the village in Scotland.
I haven't beem in Spain since 2015, so I can"t say anything.
I think it's more that Americans know nothing about food, and they don't know how to shop.
Even the bread here has additives, and it's by law. I could get nonGMO soy milk with no additives at Trader Joes. I haven't been able to find it anywhere since.
Do you buy tinned food? Check what is on the tin. Certain ingredients are not allowed. That does not mean the food is pure.