Fiber once it's installed requires effectively no maintenance and it will last indefinitely until physically broken. Copper corrodes and wears out, but glass will last longer than the people who install it or the people who enjoy its use. Satellite internet from LEO requires many rocket launches per year to sustain, meanwhile fiber means rolling a truck (which is usually relatively local) anywhere a backhoe or flood or digging animal has broken it every few months or years, and these trucks are already rolling to install and maintain all of the existing services (or install new ones)