From AI:

In both Rhino and SketchUp, "blocks" (or their equivalents) are used to group and reuse geometric elements. In Rhino, blocks are similar to groups but more closely resemble SketchUp's components, allowing for linked, editable instances. SketchUp's components are easily understood and used by beginners, while Rhino blocks offer more flexibility and integration with other design software.

It could be useful to open some discussion regarding this theme.

IMO ... "more flexibility and integration with other design software" is quite good starting point

Mik