MY COMMENT: I think it's important to emphasise just how good the hockey stick illustration is in conveying two important things - not just in conveying the benefits of becoming advanced at the point in human history at which the hockey stick's heel and toe curves upwards, but in conveying just how comparably bereft human beings were for so many centuries when they were without the things we take for granted. One can see the astonishing progression-explosion not just by how much we've reaped the benefits of capitalism, industry, science and technology in the past two centuries, but by the absence of these things in every century that pre-dated the industrial revolution.
One caveat though. While all this is a very good indicator of just how much of a progression stasis there had been in the human story until the emergence of capitalism, industry, science and technology in the past couple of hundred years, one mustn't be short-sighted and forget that not everyone has had anything like the same kind of prosperity that we in the developed West have had. While every country is a lot better off than it was fifty or a hundred years ago, there is still lots to do to ensure that the world's neediest people get to share in the benefits of this progression-explosion as soon as possible.