If you work in an industry where this isn't true, but depends on the largess/spending of people who work in industries where this is true, are you still in a la

If you work in an industry where this isn't true, but depends on the largess/spending of people who work in industries where this is true, are you still in a largely zero-sum waste of time job? More simply, how many levels deep do you carry this analysis? Also, can you guesstimate how much of the income generated in the US is not derived from zero-sum waste of time jobs/products when you carry the analysis at least 2 levels deep?