I think you're incorrectly separating the 'fabric of society' from the economy. The economy describes all things that are valuable to us as a society and that includes interactions with the staff at our local grocery shops. When you say "Economically it makes more sense to buy cheaper and faster" that is obviously not true for you and probably many others who are prepared to pay for the social interactions that local shops provide.
There will still remain room for shops with cashiers in the market just as there is still room for restaurants with waiters, tables and chairs despite the innovation of drive throughs and fast food.
As long as you are part of a large enough group who is willing to pay for traditional style shops then they will continue to exist.
No, I think GP is totally correct. Economy does not describe "all things that are valuable to us", nor does it describe relative value between things when considering the whole picture of one's life. Economy is a system of powerful feedback loops; it amplifies momentary relative value differentials. People like the human contact, but due to financial situation prefer cheaper groceries? If shops can save on cutting nice clerks out of the loop (or working them down into zombiefication), they'll outcompete ones that try to stick to "old model", but guess what - another part of the economy is right there to take away the marginal savings you as a customer just "made", and thus you're no better than before in terms of spending money, but you've just lost another nice aspect of the society.
The economy often gives us good solutions, but it also often gives us bad ones. The economy doesn't care either way.
Maybe I am incorrectly conflating Economics with the Economy. I understand your point about economic forces producing an outcome that is less optimal due to our failure to consider present and future effects of our decisions.
My point is that if you look at this from an economic point of view, you should be able to figure out whether or not it is good or bad (or at least know what information you need to figure out if it's good or bad). See my other comment on this thread: https://news.ycombinator.com/item?id=13108119
We could, as you say, analyze and figure out whether or not any given market "innovation" is good or bad, but the big problem is - we can't meaningfully act on such information. Coordination is superhard[0], and in the meantime we all make individual choices based on momentary value differentials - choices which the market will happily aggregate and amplify, whether we like it or not.
You're spot-on in splitting the problem into two in your other comment.
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[0] - especially if you frown at one of its most powerful form in a large society - government regulations.
There will still remain room for shops with cashiers in the market just as there is still room for restaurants with waiters, tables and chairs despite the innovation of drive throughs and fast food.
As long as you are part of a large enough group who is willing to pay for traditional style shops then they will continue to exist.