We miss all of these things by not being in the office:
Current work (what just happened, what’s coming up?)
Future events (e.g., a presentation, a customer appointment)
Current mood (e.g., anger after a problematic customer meeting, joy about positive feedback)
Difficulties/obstacles
Colleagues offer support when someone reports difficulties
Exchange of knowledge
Further education/training
Work process improvements
Private matters (family, leisure time, etc.)