No wrong again. Correlation does not imply causation You again make assumptions about an engine on a few specific games that you've played. You've mentioned frostbite that only EA can use, and you've also mentioned source, a very old and polished engine that lacks the majority of modern features games require. Do you want to stop making a fool of yourself? Go here https://en.wikipedia.org/wiki/List_of_Unreal_Engine_games Play all the Unreal Engine 4 games listed, or at least half. Record different game features each game uses (Physics simulation, crowds, dynamic shadows etc) Record FPS Record limitations (Loading screens, unrealistic things, obvious shortcuts/hacks to make things work, etc) And then provide some statistics Then do the same with another engine. Then you can make a comment that an entire engine is bad.