Communities that worry about investing in fiber because it might not last long enough in terms of capacity need not worry. No one has yet found the upper limit of capacity. Siemens just set a new record for the amount of data pushed through a single channel of a fiber cable: 107 Gigabits, or about a thousand times faster than the "standard" 100 megabit off the shelf network gear used today.
The key word here is "channel." A single fiber can have multiple channels, and off the shelf network gear today supports, for example, 40 and 80 channels. Fujitsu has equipment that can push over a terabit of data (1000 Gigabits) over multiple channels (20 channels of 10 Gigabits each).
This makes fiber a very safe investment.
One more thing: all these new systems use "active" networks, rather than the telephone companies preferred "passive" or PON systems. If you want to future proof your communities investment in fiber, active systems are the way to go. You won't find anyone doing cutting edge research and development on PON systems, which are designed mainly to prop up legacy telephone networks and to keep customers locked into monopoly providers.