That teaches some bad values or at least could imo, like a lack of communal sharing/living, being stingy with others, those are some odd values. It's one thing to have an adult child contribute but that's nuts.One of my friends cousins mum takes it to the extreme. She got her daughters bedroom electrically wired separately from the rest of the house (or something like that, can’t remember exactly what she said), and charges her daughter a separate electricity bill.
she won’t let her charge her phone in the family living room either and “use their electricity”, and makes her buy all her own food. I remember she used to charge her phone at college