The key advantage is that allows members who read the group's archive or digest (rather than individual messages) to have access to the attachments.
Would it be possible to have an option to include attachments in a digest? Another (now defunct) list operator used to do this, but I think if it is to be done it should be an option for the subscriber.
There are groups where I take the digest because I am interested in the conversations but not in the attachments.
