The essential lesson on offer being, and one without which we simply have no hope at all of deciding what to do next, that the good old days are right now. Further, that as long as we don’t mess up there is no reason why they shouldn’t keep getting better off into the future.
That is, roughly and imprecisely to be sure, with backsliding here and there, we’re on the right track with this economic development thing, with that just passed greatest reduction in absolute poverty in the history of our species.
Rosling wasn’t feted and awarded in the same manner that Paul Ehrlich, who has been wrong on every point concerning the same matter, has been but then that’s just how society seems to work. Gloom sells better than optimism.
All (all!) that Rosling did was stand up and tell us the truth about our world. A worthwhile thing to do with a life, don’t you think?