I was initially a skeptic of the cost of Fibre-To-The-Premises, but in hindsight for New Zealand (≈Oregon) I think a national rollout of fibre was very effective[3][4].
AFAIK fibre is more resilient to catastrophes (like earthquakes[1][2] in Christchurch or California), and having a high speed residential fibre network definitely helped during Covid.
I am uncertain what you mean by “efficient”. Perhaps link to something that backs up your opinion?
Australia and New Zealand have helpfully agreed to provide a case study in which works best. Mixed fibre and copper in Australia is slower and ended up costing dramatically more than it was supposed to.
I think it's just inertia. At higher speeds you have to do so much signal processing going over copper, that it iss costing more and more energy compared to optical. Which is limited to 2.5 Watts per port and end of the fiber, at least in common prosumer facing gear. While you can push up to 80KM(or meanwhile even more!) in one run with such stuff, depending on the used fibre and wavelength.
