Why do I need an 80$ device to check my heart rate? What ever happened to a watch and checking your pulse with a finger? Breath rate? A watch and monitor your b

Why do I need an 80$ device to check my heart rate? What ever happened to a watch and checking your pulse with a finger? Breath rate? A watch and monitor your breathing. Blood oxygen level? A $20 device on Amazon.com. This is overpriced and not that useful. Am I the only one that does not want to update my friends facebook feed with my personal health metrics?