To teach a kid about financial responsibility besides kicking them out at 18 or making a minor child pay for their basic necessities.
I’ve seen parents online talk about how they give their kids a “budget” each month for them to purchase their own hygiene products, for instance. While the child is not actually paying for their own hygiene products, they are learning to budget and weigh out their wants and needs. And many of these parents allow their children to put any money they don’t spend back into savings for them as an incentive for budgeting well. You can still help your kid learn to be responsible without making them fend for themselves!