I keep my lenses and cameras in a five drawer Sears Craftsman metal tool cabinet, in the basement. Since it's metal, there are no materials that store moisture. The air conditioning and heating circulates through the basement, keeping the air temperature and humidity controlled. I've had no problems after 19 years of keeping my gear in this way. It is a finished basement, however, and is part our living quarters, in daily use. I'm always opening the cabinet drawers, which I believe helps to have good air circulation.
So I think that whether a basement is OK for equipment storage must depend on the individual circumstances. You don't want it to be too dry, because that's not good for cloth shutters. Right now the humidity meter near the cabinet reads 45%, and the temperature is 68 degrees F.
I think in general it's good to provide for air circulation, as long as the humidity is reasonable. I would only use a sealed container if it has desiccant in it, as lamefrog and peterm1 discussed; and only if there were a humidity/fungus problem in my area.
(Why does "desiccant" need two c's? I think it looks better with one c and two ss!)
May the light be with you.