Well, it depends I guess… I mostly fly through fictional routes through unique airways that not many traffic fly through. So on a good day, sometimes I can see 3-4 traffic around me, sometimes I see them pass through below me very often. Sometimes the ones that we share the same route, I can keep seeing it in front of me in a different altitude heading to the same direction.
But other times, it could be empty especially on fictional routes that not even the real world route will fly it. It also depends on the time of the day, usually at night flight, there’s not many traffic around. But I see one or two sometimes. Then again I don’t exactly sit around in front of my screen during cruise. I usually just leave my PC or switch my display to watch something else, like watching TV, movie, or have dinner. So even if I get traffic during cruise, most likely I won’t notice them.