Even assuming your argument is correct and the world floats on with between 90-70% ‘dead weight’ as you seem to put it, GDP would fall significantly because you

Even assuming your argument is correct and the world floats on with between 90-70% ‘dead weight’ as you seem to put it, GDP would fall significantly because you have significantly less consumers spending. Not to mention that society would pretty much grind to a halt because all the people doing intangible work that isn’t counted in GDP, like having and looking after children and replenishing our human capital. We live in an imperfect world, and not everything has a utility function that is measured by headline figures