Municipal fiber is not special due to the ISP being municipal government. It is special because it is a path for a community to force a second option into existence.
Lest anyone misunderstand this post: this is an observation in wholehearted support of the linked article. It is wonderful that a community is able to move forward with getting better internet service.
Additionally, I am not trying to brag. I am very lucky to have been able to relocate as I have, and that my locations have had multiple viable options. I recognize that most of the US does not have this flexibility. Again, I offer these observations as full throated support for communities pursuing municipal fiber.
Edit, summarizing: Competition works. In my experience, the dominant factor determining ISP quality is the presence of another ISP with a substitutable offering.