Previous owner finished basement and did not put any insulation behind the drywall or in rim joists. It stays around 62F in the winter and I’m looking to improve comfort. Should I insulate it or does that promote moisture?

 

 

House was built in 1948. USA climate zone 6b. Basement is half finished, most of wall below grade with no walk out basement entry. The walls are block. I don’t have any moisture issues that I know of and the basement seems dry, no signs of moisture damage anywhere. The ceiling isn’t finished so the walls have an opening in the top and I can use a camera through the top and look down into the empty cavity.

 

I’m trying to figure out why they did not insulate behind the drywall when it would have been so easy and I’m not having a lot success with my online research. Did they leave this uninsulated to promote airflow? Is leaving this uninsulated standard practice? Should I attempt to insulate behind these walls with some kind of blown in insulation like Retrofoam to improve comfort? Or is insulating and air sealing the rim joists enough? I feel cold air coming through the rim joists. I’d rather not go through the hassle of ripping the walls out to lay in foam board/spray foam. 

 

Thanks for the help. I can’t seem to find much info about this type of situation.