If time is cost, then yes, everything has an increasing total cost.
The question is more about complexity and interactions. Does a specific subsystem interact with N modules, or with 1. If N+1 module interacts with N, then the cost of maintaining that system will explode very quickly. OTOH, if the system is revisited after that test goes green to increase modularity, reduce dependencies, then complexity is now potentially growing sub-linearly to the number of modules rather than O(n!)
The question is more about complexity and interactions. Does a specific subsystem interact with N modules, or with 1. If N+1 module interacts with N, then the cost of maintaining that system will explode very quickly. OTOH, if the system is revisited after that test goes green to increase modularity, reduce dependencies, then complexity is now potentially growing sub-linearly to the number of modules rather than O(n!)