But it mostly is. And calves likely get shot afterwards (or worse) both for population control and, well, you can't have them drinking all the milk now, can you?
Same as eggs could be cruelty free, if we ignore the literal shredding of male chicks thats happening on a massive scale.
If you want to mass produce these things, which are both produced by females exclusively as part of their reproduction cycle, you basically have no other choice but to get rid of most males or even most children in the case of milk.
And even if you somehow solve this, I still would argue that its morally wrong to even have these breeds of e.g. chickens who lay this many eggs. Their bodies were never ment to do this and they suffer from sever health problems because of this.
Milk that we can buy in supermarkets is produced by special super breed cows that produce around 30000 liters (ca.8000 gallons) of milk per year. After 6 years these animals die out of complete exhaustion or as soon as they don't produce enough milk anymore. Their udder are so big they can barely move, due to the frequent milking they are also usually infected (yummy goo, goes straight into the milk- luckily it's boiled)
If you ever talked to woman that is breast feeding, you probably found out how exhausting it is to produce a highly nutritious food for a new born.
Yes milking cows for mass producing milk is animal abuse and it is really hard to find milk that is not produced in this way. I am telling you this as a person who isn't vegan or vegetarian. I think that veganism is the way to go, eating animal products is shit, there is no way to produce them in a "good" way for 7billion people. I am just too weak.