Just my idea.
To start with, reinstate the old rule that any football club can employ at most 2 foreign players, and limit the amount that can be spent on transfers. Goal: make national competitions more interesting and severely limit the role that billionaires can play, while at the same time diminishing the financial difference between the haves and the have nots club.
In other words: the exact opposite of any development toward a trans-national competition. The current EUFA cups represent plenty opportunity for international club matches.
Football supporters could easily force such a change: just boycot all professional football games (don't go to the stadium and don't watch on TV) for 1 month. The crazy "investments" and outrageous salaries budgets in what should be an enjoyable game need to be stopped, and such a popular resistance would render these investments instantly worthless.
At the same time what it would achieve is football competitions no longer disappearing to pay-tv and tickets to actually see a match would go down in price.
I would say it's a worthwhile goal.
As an aside: there has been an actual attempt some years ago by some of the top clubs to do precisely that: create an international league of the "happy few". Luckily that turned out to be a lead balloon.
P.S. My plan won't fly either I'm afraid; the masses are too easily manipulated by big money.