> What is the value of that? Wouldn't that be effectively privatizing the gains and socializing the cost?

No, it would be having the government provide the infrastructure that we only need one of (fiber to individual homes), while encouraging competition among service providers, rather than stagnation with a single monopoly.

This works rather well where I live, in Sweden. The local government runs fibre through the community, the ISPs provide services. Hundreds of local municipalities or towns are connected this way. I only had to pay to connect my house to the fibre, access from then on is free. The ISPs (12 of them) offers services over the fibre. 100 mbps unmetered from $29/month or 500 Mbps for $79/month.

What extra value would those service providers provide? I assume here that the service level would be Gbit internet with service levels as high as electricity, which is also a utility monopoly at least here in SF.

Just like roads don't get you from A to B, cars do using those roads, cables don't transfer your internet traffic from your house to the website you're trying to reach, ISPs do using those cables.

I assume they'd provide the connectivity to the outside world.