It's a factor, certainly, though there are many others.
As for that, the dairy industry has pushed back against sodas and other sweetened beverages with its earnest boosting of chocolate milk, and against the various sports beverages with protein-enhanced "recovery drinks" of its own. It's still an uphill battle, though.
I only keep fluid milk in the house because I use a splash (1/4 cup or so) in my morning oatmeal, and it goes into my daily-use sandwich bread. Otherwise it would only get used on the now-infrequent occasions when I bake desserts, typically at the holidays. Cream and dairy products *other* than fluid milk, now...those we go through a lot of. My GF does the keto thing for extended periods, which means a lot of heavy cream, sour cream, cheeses, etc, and I generally keep yogurt on hand as well for various purposes. Milk as a beverage doesn't do it for me, though.
ETA: Wait, that's not quite right. We have grandkids who visit regularly, and they're keen on a glass of milk or a bowl of cereal occasionally, so I'd probably still keep at least a litre in the fridge for them. The 8 yo in particular is a fan of cold cereal, typically drenched in 2 cups or so of milk (of which about 1 1/2 cups go down the drain afterward, which grates on my frugal sensibilities immoderately, but so be it...).
