It’s reasonable to expect people to exhaust lower cost alternatives, that are reasonably expected to work, before stepping up costs.
This also happens if the employer switches insurance.
So no it isn’t as innocent not as simple as saving costs for generics. This makes sense for the first time the patient seeks treatment. This doesn’t make sense if the patient already has a treatment plan that works and the insurance company decides they want to do the whole pony show again, fucking in peoples life for months.
The problem is, you won't be able to hammer down the health of the patient to the lowest cost option, only the most effective.
A [relatively] well known exception is anticonvulsants. My younger brother paid for that with his life. I hope the FDA figures out how to properly evaluate generic equivalence.