Again, we can look at studies of countries who have made changes. If we're the only wealthy nation dealing with this problem at this level, shouldn't that be a data point we consider? If other countries are doing other things and getting different results, why would we ignore that?
It sounds to me you're saying, "Well, it's complicated at scale, and we can't really know anything so we shouldn't even try to think about things at scale." To me, that's just burying our head in the sand. The "at scale" emergent outcomes are very real and they can be measured, studied, and tweaked. Every individual action contributes to those emergent properties. To ignore them, to me, is to willfully remain ignorant.
"We" is nothing more than you and I (and everyone else) making rational decisions. I'm not advocating for a top-down, government-run solution here. I'm arguing for a rational evaluation of the data given our goals for the type of world we want to live in that increases well-being.
What are the authors of those studies trying to prove though?
In Australia, mass murderers chain up and burn down nursing homes (or a backpacker hostel).
Not a 'gun death' in sight, though, so no impact on the studies.
A sad/angry young man breaks up with his girlfriend; gets drunk and drives really fast into the biggest tree he knows; not a 'gun suicide' though, not even a 'suicide'.
You think the guys running studies to make Australia look like a success are going to go looking for mass murders and suicides not involving a gun, in their valiant search for objective truth?