Understand the amount of resources distributed in the game
Monitor information such as how much of the resources used for training, such as materials and in-game currency, are held by players, and what is the balance between the amount of resources obtained and consumed.
If the balance between resource acquisition and consumption is positive, you should consider content that consumes the resource.
If the balance of resource availability/consumption is inversely related, you should consider content that emits the resource. However, if the game balance is designed with resources as valuable, it is preferable to leave the amount of emissions as they are, as intended. Such resources may be discharged as rewards for playing monthly events, which can be a factor that keeps players motivated for a long period of time.