Other important thing is that paper was able to handle "all the exceptions", notes on margins, corrections, other paper clipped to it, whatever. Sure it was ugly, but it was in-band.

If there's no way to do this in a new system, then it means there will be a parallel semi-official informal shadow of it scattered around in out-of-band channels (emails, phone, paper!), and that leads to more complexity, which kills efficiency.