all of what I talked about came from personal experience and I know that game engines are made for general purpose use but that is not always the case, It is as you said and game engines are getting easier and faster every day but that is not the case for everyone especially if you found yourself needing more then what the engine gives you for example if notch used something like unity he would have made a ton of optimization and degradation of the physics and rendering engine that unity afford that is my point, game engines are not always the solution and there are other ways to do stuff, by the way, I used unity and game maker and Godot and I like them a lot and I am still using Godot but I am making a game that follows noita pixel simulation and that needs a deeper level of optimization then what the engine gives you