This also reminded me of a great post from a few years ago about why salt is fortified with iodine: https://news.ycombinator.com/item?id=38782954
I don't hope to resolve the debate, only to point out it should be possible to eat bread that is not fortified with folic acid, if for no reason than I'm not in the high risk group targeted by the FDA and there are potential benefits from reducing folic acid intake in the context of robust intake of folate from other sources.
Or, even simpler: why can't I buy bread without folic acid?
It would not surprise me that there are some places in the US that only have easy access to packaged industrial sandwich bread. It would surprise me very much if that was the norm for Americans.