I have a cast iron skillet that was my great grandmothers. I imagine a small herd of cows has been cooked on it as well as a large flock of chickens / eggs. I

I have a cast iron skillet that was my great grandmothers. I imagine a small herd of cows has been cooked on it as well as a large flock of chickens / eggs. I have paid for and thrown away several cheaper skillets during my lifetime. You tell me the difference in cheap and planned obsolescence ?