But this is just the top level view.
The distribution of urban vs. rural populations is naturally very different for different regions:
And the pace of urbanization, which has been rapid in the past, has been slowing:
So while the number of urban dwellers is increasing, the number of rural dwellers is not significantly decreasing.
Many of these small/medium sized urban areas are not urbanized cultures. They have rural-quality kinship-oriented cultures as rural dwellers aggregate into these smaller areas.
All of these trends together mean we cannot abandon either strategy to focus on one. While I have seen enough to know DMM and other like-minded strategies work in both urban and rural settings, the specific tactics employed are very different (rural areas, for example, focus on households; whereas urban areas focus on affinity groups).
We will need a mix of urban and rural strategies for many decades to come!
Graph/map source: UN Urbanization Prospects.