Participant numbers (and code comparisons) are important in many instances, and can give an indication perhaps of future trends (players and supporters growth/robustness) but the reality is that when it comes to proving anything about a major spectator/tv sport and its success, it doesn't really matter.
RL over the past 15 years has evolved into a game that increasingly cannot be played socially or by players/teams who don't train for the 10m rule game. It's following the path of American football, where few adults play the game at all outside of the NFL.
Here we keep hearing that RL participant numbers are falling in the bush and in grade football, but at the same time touch footy and Oz tag are ever growing.
While AFL, soccer & RU will continue as social participant sports, it's hard to see that RL's participant numbers (if we don't count touch/Oztag) are going to keep pace.
RL's structure below the NRL is (unfortunately perhaps) all aimed at preparing and delivering players to the NRL level. Once you (as a player) fall out of that race, the structure outside of that offers you little in regard to earning potential, insurance costs etc.
I'm not trying to paint a negative picture - it is, as I said, no different to American football, and look how successful it is as a spectator and pro sport.
The concern is that the other codes use their social/school game as a marketing opportunity. If RL's not there, then we are missing out, especially if govt's begin to increase funds for school/social football programs.