Who is going to do all the work of fighting a Trust when they drag their feet using legal grey area or random excuses? Government worked out the correct action

Who is going to do all the work of fighting a Trust when they drag their feet using legal grey area or random excuses? Government worked out the correct action a long time ago. When you see a trust, you destroy it, when you still get collusion between the separate companies that is manageable since collusion has prisoners dilemmas.