Perhaps all of Europe is (at varying speeds) following America's bad example in many things especially transport policy.
Yes you are considerably younger than me, but that's not the point. My point is that while supermarkets might be inevitable, and in many ways preferable, a supermarket with no human staff present would be not just an eerie experience but a definitely inferior and unhelpful one.
In the case of the railways the human touch is vital for several reasons. For a start, while almost everyone uses a supermarket frequently, many, many people use trains only rarely. Many of these will be reluctant to do so again if they find the system difficult.
I'm used to online transactions and using a computer generally, but I have only today given up trying to purchase a ticket online from the dreaded Transpennine (going through the National Rail app only redirects me to TPE so it's no easier). Even when it goes smoothly it is a complicated business, and at more than one attempt when I had got as far as the 'pay now' button the whole thing froze. I've concluded it will be much easier to go to the station and make a simple request over the counter. While it's still possible!
TVMs are notoriously unreliable and many stations have only one. If it breaks down, or as often happens is unusable for other reasons, for example the screen being unreadable in bright sunshine, what are we suppose to do in the absence of staff?