The person accompanying you is helping shape the moment, not merely filling its background.

Company is easy to treat as scenery. Somebody comes along to the appointment, the walk, the errand, and the day gets scored as yours with a person present, when their attention was part of what made it bearable or good. Being with someone is work of a quiet kind, and it changes what the hour actually was.

Tell the person who came along what their being there did for you. And when you are the one accompanying, arrive as a participant rather than an escort, since the difference is felt even when nothing is said about it.