Baseband is simple to install, interfaces are inexpensive, but doesn't have the same range. In fiber optic technology, the medium consists of a hair-width strand of silicon or glass, and the signal consists of pulses of light. Running current through the material generates a pulse of light. A photo diode light detector, which converts light pulses into electrical signals. Tremendously high data rate, low error rate.
Error rates are so low they are almost negligible.
Difficult to tap, which makes it hard for unauthorized taps as well. Because of its thinness, phone companies can replace thick copper wiring with fibers having much more capacity for same volume. This is important because it means that aggregate phone capacity can be upgraded without the need for finding more physical space to hire the new cables. Greater repeater distance than coax. In contrast, tapping into coax is trivial.