[thereisnospork]

And in a lot of cases it does, but the important point is that the argument needs to be framed as you've put it: how do we get everyone what the most of what they want [transportation/books]? Most cost efficiently being implied of course. Being dogmatically "anti" or "pro" anything is looking at the problem wrong.

To the specific example, removing self checkout lanes makes sense if the removal adds more value than the lanes were providing, but not if they are providing more value than their opportunity cost -- perhaps because of woefully understaffed registers and a buggy mobile checkout app the self-checkout machines are responsible for a large portion of checkouts. Which would make them counter productive to remove.

[lazyasciiart]

And since the self checkouts exist, there is no interest in paying to have librarians at the register, or drivers on buses; so the self checkout is the excuse for not providing a librarian, which effectively cuts off some users from checking out books at all.