People sometimes add detail because deciding what matters is harder.

Including everything requires no judgment. Deciding what matters means picking, defending the picks, and accepting that you might have left out the important thing, which is genuinely harder and more exposing. So people send the long version, the full data set, the complete history, and pass the work of selection to the reader. The bulk is a way of avoiding the decision.

When you are tempted to include it all, ask what the three most important points are and lead with those. Put the rest where it can be found. Doing the selection is your job, not the reader’s.