I think there's more to demographic destiny than constantly growing populations. For example, the 'demographic dividend' is a double-edged sword, resulting in economic growth if enough jobs can be created or the potential for massive unrest otherwise. (This is one problem which India and much of Africa is grappling with.)
At the same time productivity per worker has gone up dramatically in many industrialized and industrializing countries, even as (and in some cases because) of automation becoming more and more widely adopted. On one hand we're having discussions about how to handle large numbers of workers rendered redundant because of automation destroying jobs (e.g. guaranteed minimum income); on the other hand we're predicting that an economy won't have enough workers to fill all the jobs that will be created because of demographic trends. These things are contradictory.
At the same time productivity per worker has gone up dramatically in many industrialized and industrializing countries, even as (and in some cases because) of automation becoming more and more widely adopted. On one hand we're having discussions about how to handle large numbers of workers rendered redundant because of automation destroying jobs (e.g. guaranteed minimum income); on the other hand we're predicting that an economy won't have enough workers to fill all the jobs that will be created because of demographic trends. These things are contradictory.