They’re not bad, it just depends on how much you process them. Oven baked fries for instance, are not far removed from normal oven roasted potatoes. Par boiling and then deep frying them in fats will release more nutrients than you would get from a normal baker. Slicing paper thin and perfectly frying is an industrial process that most people can’t replicate at home.

I honestly think home cooked potatoes are going to be perfectly fine in most ways.