[Retra]

ECSs are sort of designed to be flexible and make it easy to extend and mix the behaviors of a game. Most games do not need such flexibility, because professional games are designed and you already know what capabilities are needed, and it is more efficient and less complex to implement those things directly.

However, if you're designing an open-ended game engine for other people to develop in, then an ECS is a godsend, because you have no clue what they plan to make their game do.