Why are US pharmacies so slow?

I took a prescription into a new pharmacy yesterday. I decided to give this drugstore a try, as it's more convenient to my home. After giving all my personal info as a new customer, and told the lady I'd be paying cash since I have no insurance. I told her I had some shopping to do across town, and that I would come back in about 2 hours to pick up the meds. This was well before noon. She actually told me "Oh, you can't pick this up until tomorrow. There are 10 orders ahead of you." There was one other person standing at the pharmacy counter when I arrived, and no one arrived behind me while I was in the store.

This was not a small pharmacy. This is a major pharmacy chain. Can someone please explain to me why it takes so long to get a prescription filled?

Also wondering what about folks who need their meds ASAP, ie, blood pressure, heart meds, epilepsy meds, etc. I have a feeling some of them are going without meds for a day, if my case is typical.

Well, I get some psychiatric meds that are controlled and even with the checks and balances they go through for that the longest I've had to wait at my pharmacy, a CVS, is about 4 hours. HOWEVER they were out of one of my meds and that had to wait until the next day when the shipment came in.
My guess? Slow/lazy techs or pharmacist. Find another!!

I'm guessing volume. Pharmacies have to be really careful about filling orders, so as to prevent all sorts of medical funkyness.

It takes time to fill a prescription. Pharmacies are notoriously short-staffed. The pharmacist can get busy helping someone. Lazy customers don't want to call their insurance, and so, we have to call them. The speed of filling a prescription is dependent upon the actual prescription itself. You can have one order with ten prescriptions in it. You people don't seem to get it that fast pharmacy is bad pharmacy.