Here are a few. Maybe you can think of more.
razors with multiple blades - 1 was fine for a long time. Then 2, then 3, 4, 5 , 6. I think it ended at 7 when the razor companies couldn't get people to pay the extra money. Really.....1 blade is fine. How long does it take to go over your face 2 or 3 times with 1 blade ?
spinal bone fusions - many doctors say most are unnecessary, and could be treated with less invasive methods. Reason......it is the most expensive treatment. A survey of doctors having back issues resulted in almost no doctors having spinal fusion done to them.
10 most used drugs approved by Medicare - the 10 most used are the ones that have gone up most in price. Government is happy to pay the drug companies. Any idea which drug companies make the most political contributions.....