The problem with satellites however is that they cannot loiter, so the window in which they can gather data is limited and predictable. They are also essentially fixed on their track - changing orbit requires fuel. Drones (and old-fashioned spy planes) do not suffer from that limitation.
Tossing a battery-powered radio in a gallon ziplock into the woods outside the chainlink for the base also works, and would have more loitering capability than a drone.
So throw it in a gallon ziplock inside some rope and stuff and toss into a tree. In any case, a drone has about 15-30 min of loitering time while a radio-in-a-bag has potentially weeks or even months. I know which I would choose for spying on radio transmissions.
What they don’t have is high accuracy pointing. If you want to listen to activity on 128MHz at a specific military base from GEO you’re going to be getting a huge amount of interference from everything else in CONUS on the same frequency. At LEO you can do much much better pointing with your antenna.
