I never used the phrase zero sum, and I don't think it's appropriate in this context at all. There's almost nothing that happens in a modern society that isn't

I never used the phrase zero sum, and I don't think it's appropriate in this context at all. There's almost nothing that happens in a modern society that isn't a good deal for some of the people involved. Consequently, "it was worth it to X" isn't much of a metric. I get the sense that you're not a big fan of the concept of externalities.