Humans absolutely can use ethanol for energy. https://en.wikipedia.org/wiki/Ethanol_metabolism We net 7 kcal/g from ethanol, (compare to 9 kcal/g fat, or 4 kcal/g carbohydrate/protein.) There's several intermediate steps, but it's pretty efficient and a dense source of energy.

Much of lipid and protein catabolism also does not rely on glucose as an intermediate. Everything that doesn't get converted to glucose first will get converted to acetyl-CoA (glucose catabolites turn into this too) for use in the Krebs cycle.