Our room steward was always nearby during the dinner hours - either cleaning another room while the people were at dinner, or just puttering about. In addition, we frequently "ran into" our room steward in the morning as well.
If you are really never in your room, it's certainly possible that you might not cross paths. But we saw ours frequently when we'd go back to the room to change clothes for dinner, or head out to breakfast (or come back from breakfast). it was actually kindof nice, because a few days the kids decided to sleep really late, and so we'd let him know that the kids were sleeping late as the spouse and I headed out for breakfast.
In fact, if we didn't see him, and needed too (which did happen once when we wanted to compliment him on a great towel animal), a short trip down the hall would usually find him cleaning another room.
The room stewards seem to pick up on peoples daily routines pretty quicky. We never once came back to the room and found him cleaning it, but he was always around (somplace) during the day.