It’s great thing to keep in mind but you make it sound like everything else in whole supply chain proces is perfect and this is the only thing that can go wrong.

All supply chain operations have many levels of risk attached to it and you always need to manage it. Main risk you should make sure you don’t have to is to depend on shipment arriving on time. Plane crashing, fire in a delivery center, last mile truck crashing, heavy snow blocking roads, etc, etc. And that’s just shipping - there’s also risk with insurance company getting cofnused with you prescriptions, credit card getting denied, pharma company having production issues, etc, etc. You have risks also with your local pharmacy, even if you aren’t disabled - again roads maybe closed, they may burn down, staff can catch some serious infection that will force closure, etc, etc

If you need critical meds, you need to make sure you always have enough of a buffer, as there’s many things that can always go wrong