US sugarcane is a protected market and is not globally competitive. US soy is globally competitive. You can’t just go produce sugarcane, because nobody outside of the US would buy it at the rates that US sugarcane farmers would sell it for.

https://harvardpolitics.com/politics-of-protectionism/

Perry points to the cost of sugar as an example of protectionism hurting the consumer. Around the world, the price of sugar is about 14 cents per pound; in the United States, the price of sugar is double that at 28 cents per pound. Perry explains that “because we keep most of the foreign sugar out of the country, the cost of higher sugar prices is spread around two or three hundred million consumers. We all pay a little bit more, every day, for anything that has sugar in it.”

https://www.cato.org/policy-analysis/candy-coated-cartel-time-kill-us-sugar-program

Barriers to imports of sugar have been employed nearly since the republic’s founding; a tariff on the product was first passed in 1789. Duties remained in place almost continuously save for a four-year period from 1890 to 1894, but modern-day sugar protectionism can be traced back to the 1934 passage of the Jones-Costigan Amendment.1 This legislation, passed as an emergency measure to provide assistance to sugar farmers and later incorporated into the Sugar Act of 1937, had as its key provisions domestic production quotas, subsidies, tariffs, and import quotas, all designed to restrict sugar supplies and boost prices.

As noted by the Yale Law Journal in 1938, the result of this market meddling was to harm consumers, while failing to serve as the industry savior the legislation’s backers imagined it to be:

Protection of the domestic beet and cane producers costs the American consumer three hundred million dollars a year even after the duties collected by the Treasury have been discounted. No attempt is made in the present scheme of regulation to encourage production in those fields which can produce sugar most economically and to discourage it in the fields which require subsidization. Thus, despite the inefficiency and expensiveness of the beet sugar industry and the well nigh intolerable working conditions in the beet fields, the latter area is the only one not really restricted by the quotas which have been imposed.

The most efficient producing areas have received the most drastic restrictions. A proration system has been devised which prohibits the State of Florida, the only area on the continent which could produce sugar profitably without a tariff or direct subsidy, from producing more than fifty percent of its own intrastate consumption. Moreover, the federal government has assisted in increasing the supply of sugar by spending enormous sums on research, irrigation, and reclamation during a period when production was already far outstripping consumption. As a consequence of these measures, legislation ostensibly enacted for the relief of domestic farmers results in a net loss to them.2

Despite such documented costs even at this early date, the system persisted with only minor adjustments through 1974, when a tripling in the price of sugar coincided with the expiration of the Sugar Act of 1948, and Congress decided against renewal. A decline in sugar prices then led to the temporary creation of price support loans, that is, government loans secured by sugar as collateral, which the borrower can either repay with interest or, if prices are too low, default on. These were enacted for the sugar crops of 1977–1979 and lapsed in 1980 and most of 1981 in the wake of a dramatic sugar price increase. A sugar support program reappeared in the 1981 Farm Bill following a price retreat.3

Officially known as the Agriculture and Food Act of 1981, the Farm Bill featured the reintroduction of price support loans that continue today and form one of the U.S. sugar program’s four key pillars. Extended through the U.S. Department of Agriculture’s (USDA) Commodity Credit Corporation, these loans are made to sugar processors at an average national rate of 18.75 cents for every pound of raw sugarcane provided as collateral (rates vary slightly by region of the country) and 24.09 cents per pound of refined beet sugar.4 These rates effectively serve as a price target for the USDA.

https://www.npr.org/transcripts/179295426