"There are all sorts of benevolent aspects of everyday life which are clearly the product of chemistry or engineering or medical science, but it's hard to assemble a collection of concrete, object-level stuff and say "all these things were made by economists!"'

There is a book, "Better Living Through Economics", (the title inspired, I assume, by "Better Living Through Chemistry") that explains some of this. It is largely stories about economists getting the government to work better- ending the draft, stabilizing prices, et cetera.