A municipality would issue bonds to fund the replacement of their water mains, which are breaking and pouring water into the streets every winter. It would issue bonds to renovate their elementary school, which has a leaking roof, asbestos insulation everywhere, and drinking fountains that dispense leaded water.
Municipalities have limited borrowing power, so muni fiber does have to compete against all those other priorities. And it's been a tough market for muni bonds lately.
What's more, muni fiber would be considered a non-essential revenue bond. These types of bonds carry higher interest rates than essential services bonds, or general obligation bonds.