The only way the top 6 can spend more than the current £500ish million budget is if the bottom 3 get more money.
So if you’re a top 6 side you can either accept your maximum budget is £500mish forever, or you can grow the PL central revenues, rework the central payments structure, make sure the other 14 get their slice of the shared commercial money, and keep growing and spending more and more like they are now.
This isn’t about capping the top clubs spending, it’s about stopping the gap between the richest and poorest growing.
The only way it can ever hinder someone is if the top 6 owners keep trying to take all the money in every new deal. As long as they keep revenue shared the way they are now, the cap will always be above what everyone is spending anyway.