I get that it isn't the same as picking a loaf of bread off a shelf, but some do seem extremely slow without any perceptible reason.
The pharmacy I used to go to would always tell you it would be about 10 minutes when you took in your prescription and it was always more like 40 minutes or so. They encouraged everybody to save time by getting their GP to send their repeat prescriptions direct to them, waiting so many days to ensure they got it ready and then going in to collect it. However, if you did that, you would go in, they would confirm that they had the prescription in and only then look at it for the first time, which they said would take about 10 minutes, but was actually 40 minutes.
I moved to a different local one and got my prescriptions sent direct to them. I now go in and then leave 2 minutes later with my prescription - and this one has free parking. If I take a new (non-repeat) script in after an appointment, they take a maximum of 10 minutes.
The first one always seems to be staffed by youngsters with only one older person there - presumably the pharmacist. I wouldn't mind at all if they were being trained up on the job, but they only ever seem to bumble around helplessly and just get in the way - if I didn't know better, I'd think they were employed solely to act as a barrier of confusion between the customer and the pharmacist and to buy time. The second one has fewer people working there, but they don't stand around looking helpless: they actually appear to be doing, fetching, preparing, checking, advising or otherwise actually working. The assistants also do what they can do and then take a nearly-finished job to the pharmacist for her to check and confirm, rather than expecting her to do all of the basic admin work herself from scratch.
I think it works both ways: it's ignorant to assume that all pharmacists and assistants are lazy and slacking in what is obviously a very important job, but there clearly are SOME who just do whatever they like, whenever they like, and don't seem to value the customer's time at all.