With 5 franchises worth of professional rugby contracts to be filled from 2 (& 1/3 [ACT]) nurseries of talent in Qld & NSW, young talented players will always be leaving QLD and NSW to further their career with the Rebels, Ponies or Force.
Often the reason for an interstate move is because of an established player in their position is a road block to them at the Tahs or Reds, with the interstate move giving a chance to get a gig in the run on squad.
Sometimes it is due to conflict with Coaching staff, or perception of a better culture or "package" in ACT, Melbourne, or Perth. An offer of a leadership position can sway a player away from their home state, as can the potential of a better chance to score a Wallaby jumper.
There are plenty of talented young athletes coming out of Qld, always have been, and always will be. Don't panic. Not all future stars are the superstars from U18 or U20 level. For many that is the peak, and they get passed by those with more determination to become better athletes.