It can be used only as half the last mile. And most don't even reach into the neighborhoods. So you still have to pay to expand that. And hope the fiber was never damaged. most of those companies have long gone out of business and the fiber sits there.
This is one company that actually uses the fiber they purchased; »
www.zayo.com/ was KMC Telecom and then Century and now its Zayo. But still does NOT cater to residential use and NOBODY will. Google will tell you how much it costs and problems they're having trying to do it on the cheap. They thought it was possible and its not. after KC they'll be done with their build. And in 2-3 years it will be closed.