In the before times you would go to a store and it was essentially a warehouse with a desk. You walk in and the dude behind the counter asked what you wanted and you gave him your list. He'd then rummage around the boxes and get you what you needed, you'd pay, and go. You didn't pick, you just paid. You could even phone in your order and the store would hold for pickup or deliver cash on delivery with options and take back what you didn't want.
Moving to a self-pick model involved the risk of theft but most of the studies showed it was cheaper to eat some theft than to employ more pickers or have customers leave because of waiting. And that's what happened. But theft has continued to rise to where now it's no longer a viable tradeoff.
Of course the recourse is back to company picking. And we now have reverted back to the old way except prepayment is required and some items can be returned... It's annoying but I see the need.
Having said that, if I'm in a store to self pick, if what I need is locked away I just leave anything else I collected there and walk out. I'm not dealing with that.