The health insurance industry has a term for this sadistic practice. It's called "step therapy." If the choice is between a more expensive medication that works and a cheaper one that doesn't work as well and might have worse side effects, the insurance company requires that the cheaper drug be used first.
One benefit to the insurance company is that the patient on the cheaper drug might die before they get a chance to use the drug that works but is more expensive. That's money in the bank for the insurance company.
Or, the patient might be so worn down and harmed by the cheaper drug that they just give up the fight to get the drug that will help them. Again, that's bank for the insurance company.