<p><pre><code>   underestimate the practical difficulties
</code></pre>
My point is not that this is easy&#x2F;hard, but rather: it&#x27;s easier to
provide top notch infra structure for the worlds population if it is
concentrated in a few dense urban centres, rather than spread out.  I
find this hard to contest. Just think about distance, bearing in mind
that the cost of sewage systems, rail (over- and underground),
fibre-optic cables and so on basically tracks distance.<p><pre><code>   if you split everyone into groups of 200k to 2m 
</code></pre>
This is an interesting point. B b b but ...<p>I cannot think of an <i>existing</i> city with 200k inhabitants and
great infrastructure.  I can&#x27;t even think of a city with 2m
inhabitants whose infrastructure can compete with world leaders such
as Tokio, Manhattan, Hong Kong and the like. And even in these places
the best infrastructure is found in the densest parts of the city, not
in the outskirts.<p>Note that the cities you have in mind, say European cities of
200k - 1m size, are rather spread out, and low density. I have lived in enough of those.<p>But it would be really interesting to have cities that have 200k - 1m
inhabitants and are extremely dense like central Hong Kong. Such small cities may
be big and dense enough to have the economies of scale of their larger
rivals. But, as pointed out by &quot;vidarh&quot;, they would not
remotely match megacities in terms of interesting cultural life.<p><pre><code>   not a hypothetical, 
</code></pre>
I don&#x27;t think it works that well. European cities of 200k - 2m are
car-centric in my experience. I supect China would run into major
problems if its population live in low-density European style cities
with 200k inhabitants each.