If you're doing science, you can't rely on "obvious" to be your answer.

You still need to test your assumptions. Sometimes common sense is just wrong. Besides, some of this may simply be the fact that granular data wasn't available before.

New techniques, broader availability of mobile devices and internet connectivity, it could be that the ability to break down granular data simply wasn't possible in a lot of countries.

And even further, what are the patterns which we can learn help people live longer, better lives? Is the divide exclusively rural vs urban or are there other considerations.