HFCS isn’t even just one product. There are different blends that are all HFCS. At the extreme, HFCS-90, is far FAR different than table sugar. HFCS-55 is close to table sugar (which would be numbered “50” if table sugar used that same numbering scheme), and there’s HFCS-42 which is farther away from table sugar.
The Corn Refiners Association (CRA) have been successful in rebranding HFCS under a bunch of different names so you don’t know it anymore. Current labeling has HFCS-90 (the worst kind) simply called “Fructose” on ingredient labels now. source