Health insurance in general is the problem; PBMs/discount cards are just a cherry on top. Insurance is fundamentally incompatible with clear and consistent pricing.
Pharmaceutical companies, hospitals, and doctors are free to charge by the medicine, by the night, and by the minute.
For example, this place does it:
https://surgerycenterok.com/surgery-prices/
Insurance companies do not force the sellers to use complex billing practices, they would benefit from more transparent pricing (since they are seeking to pay less).
The root cause is healthcare is inherently complicated and complex, it has a problem of supply being nowhere near demand, and since prices for things are so high (including liability), there is a lot of cover your ass and fraud prevention going on.
Germany has health insurances and they don’t do that nonsense. They fulfill their task which is to spread the risk over a wide range of people. That’s what insurance is for.