That's absolutely not true. Parents are legally entitled to use coercion and punishment to force children to pay for their own upkeep. That's one of the key reasons people used to have kids until relatively recently--for help on the farm.

Go ahead and beat your kid because he's not doing the dishes. Feed them sub standard food and not enough at that. If he talks back at all, throw him in an empty room for a week or two with no human contact.

Let's see how long you can do that before the government and society come down on you

Edit: I don't think "relatively recently" even applies here. Child labor laws were passed long before we had laws allowing things like mixed race marriage, gay marriage, civil rights for minorities, and other social changes. We are no longer an agrarian society that needs mass free labor to survive

I think the tenses are inconsistent in the sentences you wrote there.

Life has more value in well off western countries today. Child mortality is low. Families have few children. So no, you can’t abuse your kids, the state doesn’t like that.