Transfer fees have a net cost of zero to football clubs. For every fee paid, there is one received. Capping them serves only to cap the reward for developing players. If that is your intention then you have found a good solution, but if you want to make football more financially stable you’ve done nothing.
Wage caps have more merit, I guess there’s a long term risk that other leagues without the cap would sign the best players and eventually China, say, would be the global football powerhouse like Europe is today. Foden would sign for Beijing United and we’d be left with the 2030 equivalent of Joey Barton. Our leagues would become less of a global product and would lose the TV and sponsorship revenues that come from that. I’m not sure if that would outweigh the benefits of lower wages or not.
Then, there is the question of if these measures are even legal. It is effectively separate business acting as a cartel to drive down wages. A way round that is to set up a single league entity and have the clubs be mere franchises. This isn’t something that most would want, as it could result in your franchise being moved to a more desirable location a la Wimbledon.
Perhaps the best solution is to establish a commercially attractive European league for the biggest clubs, which would then provide large solidarity payments to the national associations to develop the game. They could call it the ‘European super league’...