Your suggestion were discussed a lot of times and we always got to the same result: it will only increase the gap between big amd small clubs.
Most teams playing WCC have to split their strenght when playing both sides, it might happen that a strong team might not finish in the top 3, but they won't finish in a lower position than 5th or 6th at most.
If we add another competition, those teams will keep playing international competitions, collecting extra money and experience.... you might see a chance to get a place if you play in a lower ranked league, but in long term it will make the gap even bigger than now.
To be honest I do not quite understand the reasoning, is not that how real football works, is not every nt cup winners teams allowed to play on
Europa League and managing your players fatigues is what all teams do in the world. I think it would add so much more interest to the game about the money give teams who play in
Europa League as much as they would get if they were playing friendlies