ECS is the "microservices" of game development : it's touted as the way to go, and in some cases it's the best solution, but it comes with increased wiring complexity cost, and the hype surrounding it causes it to often be adopted for dubious reasons (e.g "deep class hierarchies are bad, therefore I need ECS").
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.
