Perhaps they aren't intentionally getting drunk, but merely trying to get those calories and being drunk is a side effect?
Being drunk as a bird wouldn't seem to be a good idea from a survival point of view ...
In a very back of the envelope kind of way, here’s why: Alcohol is metabolized not as nutrition but as poison, and while yes, ethanol is very calorific, the calories derived from are lost (mostly) as heat. And, because of the metabolic pathways utilized, other important substances required by cells are depleted (products of the Pentose Phosphate Pathway - PPP) in the quest to detoxify alcohol. Running the PPP is generally an energy intense process, so you’re at a net loss when al said and done. This can partly help explain why chronic alcoholics are not overweight. This is excluding the calorie debt owed to repairing cell damage from the cytotoxic effects of alcohol.
If anyone’s interested, I can recommend some Biochemistry textbooks for a deep dive.
EDIT: Forgot to mention, partly thanks to the metabolic reasons, alcohol results in hypoglycemia, so it is unlikely that the bird would experience feelings of satiety after imbibing.
Being drunk as a human is also not a good idea from a survival point of view given how often drunk people kill themselves doing stupid things.
Crows engage in play and form complex plans that show they understand that actions have consequences so it doesn't seem unreasonable that they might occasionally decide to get drunk and roll around on the floor screaming.