However—and I’m not saying this as a defense, just as an interesting fact—at one point when I was waiting around trying to get the attention of someone to buy a stupid dongle, a staff member helpfully pointed out to me that I could just buy the thing myself with the Apple Store app on my phone (i.e. point my phone at the barcode on it, pay with card), and then walk out out of the store with the item, having never interacted with a single store worker (except perhaps implicitly with a plainclothes security guard who observed me doing this self-checkout flow and so didn’t tackle me on the way out. I don’t think your purchase is somehow remotely deactivating a magnetic anti-theft tag in the product or anything, so they’ve got to be doing loss-prevention for this flow the old-fashioned way.)
And while you can’t complete the entire purchase yourself for big-ticket items (the kind they keep back in the warehouse section and would have to retrieve for you), you can still do the “paying” part in advance of showing up at the store, through the app—or while you’re in the store, through the app—which turns the process of “finding an employee who has time to both guide you through SKU selection and ring you up” into “getting the front-door attendant to notify anyone with a spare moment that one of the devices already in the ‘waiting for pickup’ pile in the back can be grabbed and brought out.”
Honestly, this seems like it has somehow secretly become the primary flow that Apple Stores want to do [non-business-customer] purchases through, and yet they don’t mention it anywhere. They should have big signs in the stores telling you to buy things using your phone (and/or by using the store website on any of the demo computers)!