After grad school I lived at home for about 9 months. I paid for my car insurance, health insurance, and phone (this was before the days of streaming). I can’t remember if I paid monthly “rent” or not, but I do know that if I did, it was all returned to me when I bought my first place. I did not have to help buy food for the household either.
I suspect that if our kid came back to live with us as an able-bodied adult, that we would expect similar financial independence.