It is obvious that range is important for connectivity. But what is remarkable is how non-linear that effect is. That is, the number of nodes you need in an area to create a connected mesh network grows super-linearly as you reduce the range. This means that short-range technologies like WiFi for mesh networks are going to struggle to get critical mass.
Here is an article that I wrote that gets deeper into this and compares the connectivity profile of WiFi-direct, LTE-direct and goTenna based meshing.