It's very simple, I found it very interesting to put the size of the world in the game. I could tell that my world has a different file size than I planned, for some reason at the time of compiling the junk is taken along. I am not an experienced creator and these things always go unnoticed for me (may be the problem of many).
For optimization reasons I would like to see the size of my worlds and avatars in the SDK on Unity. both in the "manage uploaded content" and in the "show build control panel".