On the other hand I was listening to a podcast when I popped into boots to buy lunch. Fairly busy so there was a queue, I drew the short straw and got directed to the legacy kiosk. This means having to pause what I was listening too, lose concentration, and switch into conversation mode for no benefit at all.

Ikea is simply far easier to self-scan. Back in the olden days you could scan your shopping in the supermarket as you put it into the trolley. Rather irellevent now when nobody does a "weekly shop" in person any more but far better than the "put into conveyor". Go back far enough and you used to have to ask someone for every item you wanted, no self picking.