> Comcast's oligopoly is largely established by the fact that rights-of-way and pole-attachment rights are monopolized by municipalities, which tend to approve only a single, or few providers.
Only because, when municipalities do try to treat bandwidth as a public utility, which they can sell to all providers equally, Comcast and other large ISPs sue them.
> It's not a natural monopoly.
I agree, but I don't think it is primarily local municipalities that are propping it up.