When you are planning a route, at least in my country, you need to fill flight plan, according to plan you need to make nav log, to do other prep (call local met office for weather, call respective tower to announce that you are going on route or starting your flight plan, to get QNH and basic info). If I'm not wrong all of that is not necessary when in traffic pattern. Point with cross country flying, at least in my case was to get know some other places around, to strengthen situational awareness and to enjoy one specific dimension of flying (without FI to press you do this, do that). Also this helped me to strengthen my decision making as you are PIC and have to deal with all stuff which come to you (constant frequency change, area control change, entering airfield areas with high activity, avoiding/be aware of incoming traffic etc). Also for me was the moment to learn my country topography, to learn to land on other airfields as they can be specific (strong winds, high mountain nearby, shorter strip, narrower strip). If you ask me hour building was for me best experience so far.