You said: " so there is no way to add the record to more than one person at a time - no option to add other members of the family at all; even the primary person to which you are attaching the record must be entered manually. I have spent countless hundreds of hours adding the same fact to each member of a family..."
It sounds like that you are using ancestry.com trees?? Were you aware you were posting in an FTM board?
1) FTM will allow copying once and pasting citations over and over.
2) FTM will also allow copying a fact, with a source and related media, and then pasting that fact to a desired person, their parents, siblings, spouses, and children, all together or by choice of which ones to include.
So, if that is an issue for you, you might want to get FTM.