Rant: Why is diaper rash cream such a scam?

We've tried Pampers Swaddlers, Pampers Pure, Pampers Swaddlers Size 2, and literally three different rash creams and my daughter STILL gets diaper rash twice a week. Is anyone else experiencing this or are we just failing at the basics? We change her constantly, use wipes that say gentle, don't use too much powder. What am I missing?? This is driving me up the wall.