Why isn’t there the same amount of Adult MITF as there are regular MITF?

And why does Adult MITF stop at something equivalent to something in the intermediate range? Correct me if I’m wrong and explain maybe? I want to be able to challenge myself with any and everything figure skating has on the table and I know I can continue to learn past Adult Gold but I was wondering why it stopped at a certain point and if this affects how far you are able to compete or something.