On the other hand, 3 years from now, the typical house will have approximately the same sewer needs that it has now.

What perseusprime11 is pointing out is that the typical house will consume much more broadband in a few years than it does now, not just the houses with carefully chosen stories.

I don't understand how this relates to whether broadband is a natural monopoly. Certainly it's one that demands more frequent upgrades, but that seems to be missing the point.

A physical fiber strand is mostly agnostic to the technology used (yes I know there are differences).

The government should lay fiber to every home and business, then sell access to that fiber at cost. Let ISPs setup equipment racks at a local POP and do the termination & CPE.

Now you can innovate by replacing the equipment at either end without digging a single trench.

I think the key part is _every_ 3 years. With the sewerage pipes, you can plan around the maximum capacity of the house, and the required capacity of the pipes will remain pretty much constant. You don't have the same upper limit on Internet capacity.