> There's 5 billion people with a smartphone worldwide

There are more than 8 billion people on this world. By your own account, 3 billion of them do not have smart phones.

> The device hurdle is gone.

Evidently not. There are a lot of countries that still have a smartphone penetration rate of <50%.

We're talking about people with low income here. We're talking about people that cannot even afford bicycles for transportation.