For most of the WT history someone on the GB had a very active roll in producing content. Russel, Rutherford, Fred Franz, Ray Franz were all prolific writers of propaganda content.
I am not aware of any GB members today who are as actively involved in producing content and a primary reason for the recycled food and dumb down content IMO.
For this reason I say they are dumber then previous members.
For what they lack in writing ability and producing new spiritual content, they more than make up for in shrewedness.