Its prescribed as a pain killer for chronic pain, and post surgery pain.
how is it better than the stuff that existed before?
It’s most often used IV as an analgesic in anesthesia practice. It’s a rapid acting short lived narcotic. You are incorrect as to it’s main use
fentanyl is a lousy drug for chronic pain. Too short acting and the transdermal preparations are erratic and dangerous for those around the patient. It is however a great drug for conscious sedation for outpatient procedures, pain relief during general anesthesia and deep sedation in the ICU for vented patients. The schedule 1 designation is a disaster