Earlier quoted context omitted.
"extreme poverty" is a very arbitrary threshold and some charts are using a fixed threshold that is based on purchasing power and not updated based of *real* cost of life compared to what goods and services are enjoyed by less poor people. Furthermore, inequality is actually rapidly increasing in many societies. Yet, one can cherry-pick an arbitrary threshold making the whole analysis profoundly misleading.
>that does not updated based of real cost of life Does being adjusted for PPP not do that?
Without understanding the distinction between PPP and USD, it is not possible to fully comprehend the article.