game engine

So, you were refuting the "supported everywhere" bit. I'm not going to argue with that.

But I will point out that there is a difference between a format that is good for interchange and a format that is good for a game to internally use for rapid loading. I mean, games store things in a lot of ways that you wouldn't want to use for interchange. Games will have textures compressed in texture formats that can be sent straight to the video card, but are relatively space-inefficient; you'd want to use PNG or JPEG or something like that for interchange. You'll often use ZIP to bundle multiple files together; it's not necessarily because it's an ideal archive format, but because it provides indexed access to individual archive elements. Many games use WAV or other uncompressed audio formats that are cheap to load but not terribly space-efficient.