Writing is easy.
Writing well is not.
Anyone can write, but not everyone can write something worthy of a reader’s time and attention.
A serious writer knows that writing is a journey, unique in the way that you never actually arrive at a final destination. You may finish an essay or a manuscript, but there’s always the next thing to write.
Just as one is never done learning, one is never done improving upon their mastery and manipulation of language. Even those authors who are the most widely read would tell you that you’ll never be the best there is — because there is no such thing — but you can always be better.
You can expand your vocabulary and grammatical savvy. You can learn to think more critically and express yourself more creatively. You can become a more proficient editor of your own work.