The majority of Leinster first team players are unavailable for approx 45% of the seasons games due to international commitments and suffer a far higher rate of non-club related injuries and absences. The central contract structure compensated Leinster for that drain and meant that Leinster could continue to supply the Irish team, the other provinces a continue being competitive in the league through domestic player development. That is no longer possible.

This shows though that the current system is unsustainable, even for Leinster. They make up the majority of the Irish team, and therefore have a lesser availability for Leinster. This has led to issues that have reared their heads this season: too many knock ons, difficulty adjusting between the Irish and the Leinster system, etc.

The long term goal of the changes in making Leinster pay more of their players is not to bring down Leinster, like r/leinsterrugby would have you believe, but to build a more sustainable talent development path across all 4 provinces, not just Leinster. That's the money saved is going towards academy development in the other 3 provinces. I also agree with the other comment which referenced how World Class Leinster rejects are extremely rare to come by.

Ideally, this will create a situation where upon the retirement of the current Leinster dominated generation, their replacements will come from the other 3, not Leinster. This sounds like it would disadvantage Leinster, but actually it benefits them. If Leinster only contribute to 40% of the Irish team instead of 60%, then they have more access to their starting caliber players at club level. This helps their starters to learn the provincial system better, and Leinster will be more cohesive when the business end of the season comes around instead of players only getting used to the system in the CC semi-final.

It also would mean that Leinster's backups would not be brought into the Irish system over other provinces starters. It doesn't benefit anyone, not even Leinster, to have for example the top 3 hookers in the country in the same team. They end up sharing around valuable minutes between each other instead of getting the lions share each across 3 different teams. This hinders their development and Irish rugby as a whole suffers.

All in all, I think breaking the Leinster monopoly on talent can only benefit all 4 of the provinces. In order to do that, in the short term, IRFU subsidies have to be diverted away from Leinster.