You can drown in your own prose, unable to to achieve basic clarity and competence. The academic language is still something you aspire toward. That is stage one.
Or, in a second stage, you are evenly matched with your prose. You can say what you want to, more or less, but you fall into stiff clichés. Little or your own personality or vision enters, because you are always saying "in this article I will argue that..." It's serviceable, without being pretty.
In the third stage, the words are doing what you want them to. Your prose is expressive, elegant, elastic, without affectation. This is not necessarily perfection. You could still write a bad sentence or two, but you are in control of the tone, the lexicon. Your own personality can emerge because you don't fall back into predictable patterns. You can be solemn or humorous, but it is your choice.