I use a lot of sketches often. On the one hand for attaching fans and compressors and so on, on the other hand we have often the same rotation basis for our attachment of dowel pins and so on.
I would love to have a central libary (maybe just for me, maybe for the whole company) in which I can manage all the blocks from one platform.
Think about things like specialized extrusion profiles you use over and over. Sometimes you just want to draw a concept and don't want to place a ipart, because you only need the 2d data.