While I completely agree with you, I think we also have to mention the customer experience, which I think is only good if those machines work as intended - which is rarely the case nowadays, with shop assistants constantly having to butt in whenever the automatic till doesn't measure the weight of your stuff properly (although it can change with AI).
The only time I've has problems with the self-checkout weighing at Tesco is when the checkout is faulty, at which point I've just switched to another one. The only human interaction required is when I buy something that's age-restricted. Which is stupid, because the human who approves that purchase never checks my ID, they just wave it through regardless, so the "check" is pointless; it's just there as a box-ticking exercise to prevent Tesco from getting into trouble.
And I recently switched to a different Tesco which uses scan-as-you-shop, which is fantastic. Still has the human-age-verification requirement, but no more weighing or packing your shopping at the end; you pack as you go, and your sole interaction at the end of the trip (apart from the possible human approver) is to make payment.
I'm absolutely convinced that the people who whine about self-checkouts and scan-as-you-shop are the chronically lazy, and/or those whose lives are so sad that the power trip they get from requiring a cashier to pack their shopping into bags, is all they live for. Neither is a valid excuse against progress.
Some may argue that human interaction is preferable when shopping.
What those people are actually saying is "I want my hand to be held because I am a child who can't be bothered to learn simple new technology", which isn't an argument. I have no time for such nonsense - and thankfully, neither does evolution.