The primary lobby of those bills was the pesticide giant Bayer (who bought and absorbed Monsanto) with backing from several of Iowa's industrial farming organizations. They launched a giant ad campaign to "control weeds, not farming" alongside their bill to influence opinions.
Also, non-organic oats are typically harvested by first spraying RoundUp (glyphosate) on them to dry out so farmers can use slightly less diesel to harvest them while fucking over the consumer's health.
More details of various tested products for glyphosate concentrations (doesn't represent a permanent rating because sources and suppliers change and there's about zero real surveillance): https://mamavation.com/food/glyphosate-bread-oats-legumes-pr...
Food in America is largely a minefield with some difficult-to-avoid hazards.