The problem is that you're looking for a terminology that says that one is a better form of the other -- that it is more. So, more dimensions is clearly better than fewer dimensions, so this terminology fits your conception that roleplaying has an arc of worse to better. I reject this concept outright. There are different ways to roleplay that achieve different goals. Playacting for entertainment purposes, for instance, is very valid and I engage in it often, but it's not superior to not playacting. It serves a different goal.
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