Yeah, there's a lot of people/investors that bought up these sites without really understanding them.
They were designed for point to point microwave paths, that was it. Some had 2 way radio capability for the US Government, but not all sites. Usually it was for aircraft use.
Not all of them are in good radio sites, as in not in advantageous locations that were ideal for 2 way radio coverage.
Many cell carriers have utilized some of the towers that were on suitable high sites. Crown Castle/American Tower own some. Not all the locations were useful, though. Some are out in the middle of nowhere and had little value.
I've been to a number of these in the Western US, and there are a lot sitting empty.
But, yeah, some area great sites, and would be useful to amateur radio operators.