Why do my kids say I am cruel and unfair?

They are 17. I treat them completely different than their older cousins aged 25-32. I do not allow them to eat snacks during the day. They both weigh 125 lbs at 5'6. Their older cousins are all 130 lbs and 5'9 they were allowed to at my kids ages. I do not allow either of my kids to drive as I refuse to teach them how. Their older cousins were allowed to learn at their age, their older cousins pick on them for not knowing how. I do not allow them to have friends. I have had them doing online homeschool since they were 9 I refuse to get either a new ssn and ID and refuse to drive them to get jobs they refuse to walk in the roads Why are they like this?