Clubs living within their means should be a fundamental concept as it applies to about every other corporate entity in the world. Spend more than you earn and you are on the fast track to financial ruin. The real question is whether UEFA can properly audit and enforce such rules and outlaw ridiculous contrivances such as Mancity where basically the same company own the club and throws a colossal sponsorship deal completely out of kilter with economic reality at them. Or ManU who have a separate deal for their club kit and the training bib. I mean how ridiculous can you get?. <Maybe we can get someone to sponsor out toilet rolls at the emirates crappers.
UEFA if they mean business should also enforce more equitable television deals across the individual leagues and stop the lopsided deals that Barca and Real have in Spain that stifles the other clubs and perpetuates the Hegemony of those two. When will anyone other than Barca/real win the Spanish league.
If we need any other example of why this system works you should look at the US where most teams have near equal spending power and the respective championships are not the predictable 3 or 4 team round table that you find in the EPL for instance.