The funny unique characteristic of the economic science is that it’s almost the only science without experiments. We can have a multitude of tests and get close to reality, but it’s impossible to reset the initial environment, control variables or test in isolation. You can’t reset people’s minds, so reproducing twice on the same island won’t give the same results, reproducing on two islands won’t either, and reproducing with 3 months delay won’t put you in the same season. Even biology and psychology are much more controllable. It’s definitely a science, but with the same criticism as chess being a sport.
I don't disagree at all with any of what you have to say, but indexing returns to a "category" does go some way toward accounting for e.g. the overall decline of brick-and-mortar retail and malls.