If "food" were a singular universally used product, and units of food were totally interchangeable I'd say that food should be treated like a utility. Instead there's a lot of different types of food from ultra-processed crap that's sat on a shelf for years to whole/fresh foods and everything from the skill of the manufacturer/baker/chef to the quality of the ingredients used will result in massive differences in the food and its costs.

That isn't really the case with water and power (or even internet access). Water is water. Electricity is Electricity. There's no artisanal organic Electricity made from the finest ingredients that powers your stuff any better. You either have a safe, functioning product or it isn't. Everyone needs the exact same stuff, it makes sense for the government to supply it. Not everyone needs, or even wants, the same foods.

Not normally considered infrastructure.

Food distribution networks might be infrastructure, but POS stores aren't, generally. Drinking water supplies are infrastructure; drinking fountains aren't.

Food production is largely nationalised due to heavy subsidies provided to farmers. Different countries have different policies here, but in my country of Australia it meets the definition of a nationalised industry by everything but name.

Food distribution as not, and again in my country we are having constant investigations into monopolistic anti consumer behaviour by the large supermarkets.

they sell water, too!