Which shops have a Z pattern? Which shops move products around? I've never seen that.
Costco certainly doesn't Costco has aisles, and sections for each major product category. IKEA has a "tour the store" design which is nice for a store you browse because you want something for every section (room in your house). You can go directly where you want if you know what you want.
For example, in Aldi stores, the milk is usually kept quite near the entrance, along with the kind of things you'd keep in the fridge (butter, cheese, etc) and the bread. In the likes of MS and Waitrose, it's usually somewhere near the side of the store, not too far from the entrance but past the fruit and vegetables. Same sort of deal with Tesco, Sainsburys, etc. Smaller convenience stores are usually just kind of random.
Nah, if you want real exploitative design, note how many shops are designed to draw out your shopping time as much as possible, by having a nice Z pattern that 'encourages' you to trudge through the whole store before ending up at the checkout. I think in that sense, most over here seem to have taken inspiration from the likes of Ikea or Costco more than anything else.
There's also the obvious 'fake sale' dark pattern, as well as the 'move everything round every few weeks to disorientate regular customers' one.