Deliberations are a specific form of discussion that are intended to reach decisions.
The key is that deliberations that don’t produce decisions are considered to be failures. Think of a deadlocked jury - if a jury can’t agree on a verdict, then the case has to be retried. That might aid the accused, but it’s a waste of time and money otherwise.
Because deliberations have a goal, it’s very important to have a good idea at all times how close the deliberation is to reaching that goal. Very few of the tools that we have help us determine that.