I made a good faith effort in researching this, and here are some examples of interaction you might be alluding to:
1. The doctor made an obvious mistake in dosage or a might not be aware of safer alternatives and the pharmacist contacts the doctor to verify that there wasn't a mistake on the prescription or mention those alternatives and see if they can persuade the doctor to change the prescription. Great, no issues with me. Everyone makes human mistakes. I do it in software also.
2. Something obvious they can see about the patient gives them some information that contradicts the prescription (i.e. an obviously pregnant women being given a drug that's dangerous to pregnant people). Again, they contact the doctor to inform and verify. Again, no issues from me.
3. Patients sometimes see other specialists and get prescriptions from them without informing their PCP (sometimes on accident), whereas a pharmacy probably sees all of these prescriptions, and can catch when two prescriptions could have dangerous interactions that a PCP or specialist might not realize they were causing because they weren't aware of the other prescription. Again they contact the physician and verify. Again, no issues from me.
4. The pharmacist has a religious reason not to want to fulfill a prescription. Some states that's allowed, some they aren't. In those where it's allowed, most pharmacies have a policy that they must allow another pharmacist at the facility to fulfill the prescription or help transfer the prescription to another doctor. Fine with me.
Note that for the first three, they generally contact the doctor and verify/try to persuade, not outright override and refuse. They help catch problems, not generally cause them. It looks like there are several states where pharmacists are actually required to provide medication[1], although that link mentions specifically personal beliefs, so I don't know if it applies for the other three issues as well.
If that's all you mean, then I don't think we disagree actually. But it doesn't look like it's as clear-cut legally as you were suggesting before, and I'm far from alone in thinking that pharmacists can't just decide never to fulfill a prescription without a damn good reason (i.e. it's definitely going to kill the patient).
[1]: https://www.nbcnews.com/news/us-news/can-pharmacist-legally-...