The sugar industry in the U.S. is protected by high tariff walls. That’s why you pay much more than the world price for the stuff — and that’s why the food industry uses so much HFCS as a substitute. So yeah, government policies are at the root of the problem — but, for very different reasons than you posit.
You are 50 years behind. The US Sugar Act was eliminated sometime in the late 70s. We do not pay more than the world for sugar except for the heavily subsidized European sugar. Additionally, the US pays more for foreign sugar to those nations who have IMF money guaranteed by the US. In addition to government rules and regulations, EPA, OSHA, etc impose costly restrictions on US sugar producers not imposed on foreign producers. Nobody tests foreign sugar imported to the US for prohibited herbicides / pesticides. We do not know nor have any control of agronomic practices outside the US.