Indeed, but the arrays that are used for holding the data are allocated (not in GC heap) before the main loop and always reused.
Yes, I merely tried to point out that you don't want to spend a lot of memory for dead objects waiting for the GC to kick in. You can use that space for caching data or loading more detailed graphics. Besides you define a minimum amount of RAM that you game will work with and try to stay within those bounds in order to increase the market for your game, so you never have enough memory for the bottom line which is what you optimize for…
I assumed GC would be useful for AI/game world. It will benefit from GC because you have complex interdependencies, many different classes and want to be able to experiment. Experimentation and explicit memory deallocation is a likely source for memory leaks… However this will only work well with a basic GC if the AI/game world representation consists of relatively few objects. So it limits your design space.
I agree that GC isn't all that useful for graphics/audio because you have a small set of classes with simple relationships, so I never assumed you would want that.
