There are articles such as this: https://www.pharmacytimes.com/contributor/douglas-jennings-p... , suggesting that some contracts forbid pharmacies from mentioning a cash option to patients. Which should be illegal.

They have gag clauses that prevent them from doing so

Why Your Pharmacist Can’t Tell You That $20 Prescription Could Cost Only $8: https://www.nytimes.com/2018/02/24/us/politics/pharmacy-bene...

Even doctors don't have an obligation to serve the patient's financial interest. I used to work for a Chicago-based company, and they offered Blue Cross / Blue Shield of Illinois. In California, where I live, these are two separate insurers. The doctor's office got to choose which run to my treatments through.

After finding that they were doing it in a way that was advantageous to them and disadvantageous to me, I asked a friend who works in medical ethics and billing whether doctors have a duty to serve the client's best financial interest. I was surprised the answer was no because lawyers (my former career) certainly are required to do so.

The pharmacists are beholden to the large companies that control their paychecks.

depends on the deal. Copay might be higher in one case but it will discount other cases. So overall it might be higher for this patient for but for everyone in total its cheaper.