Fiber is provider-agnostic. Which electrical wiring to run? Most phone companies provide service over twisted pair to the house, and most cable companies use coax. Fiber is essentially a universal medium, and the telco will provide (or spec out) compatible equipment to be installed in the home.
Fiber is the future. Most major telcos have some sort of next-gen internet offering based on fiber. And everyone's fiber service is better than their copper/coax service. Since most of the cost is digging up and filling back in, you might as well spend a little extra to make it worthwhile. There is no reason to tear up the entire neighborhood just to install some obsolete technology.
Fiber is easy. In the past, running and splicing (aka, fusing) fiber was very difficult and therefore expensive compared to copper/coax. This is no longer the case. Fiber has outgrown its early-adopter and premium-price taxes for the most part. Experienced techs are now commonplace. You no longer need a huge box mounted on a pickup truck with a generator to splice fiber---there are handheld units. The tech has matured.
Running copper/coax now is like building a cobblestone road. You certainly could do it, and it would essentially work. But this is not something you should do anymore unless there is a specific requirement to do so.