Which qualities, specifically?
I don't doubt that the league talent pool is as strong as ever, and yes probably stronger than union juniors which is largely pointy due to the dominance of private schools. If you have a broader base, you can build a higher peak.
But the skill is being bred out if league except if you wear 6 or 7, or occasionally 9 (very rarely 1). There appears to be two ways to score tries - kick in the air, or kick along the ground. The coming dominance of Islander kids is thing to have massive upheavals for league moreso than union, because of the numbers. The players are getting homogenous in their shape overall, and in their skill levels.
In Union there is still multiple roles, body shapes, and requirements to make it all function happily. This diversity also dilutes the numbers further into categories, where in league you are either one of 2-3 playmakers in the team, or you're not.
Interestingly, I was watching one of the Fox panel shows for NRL and such notaries as Ikin, Kimmorley, and Tallis were discussing the shortage of talent in the current system, holding up certain clubs (think Tigers and Parra) as examples of ordinary lists.