'The Stars incline, they do not compel'.
One of the most common debates against astrology is that if it's all written in the stars, it takes away our free will, which is our birth right as humans. This to me is the opposite of what this ancient tool is meant for. The study and practice of astrology is to enable us to use our free will with more wisdom.
Imagine that you are on a blind date. At first the only information you have about the other person is what your friends told you, she is nice, works as an accountant but has a fun side, likes to go salsa dancing. You think, stable job, likes to have fun, sounds interesting. After meeting her, you find out that she was born in a different country and moved here because her family were refugees, not only that, she put herself through college working three jobs because she always dreamed of being a writer and the only reason she has the accounting job is because she has always naturally been good with numbers and it's a way to pay the bills.
Now you have a more full bodied idea of what she is like, and you can have a better feel for your compatibility with this person.
Natal astrology is like that. We all have layers, like onions and natal astrology gives us more information to work with about ourselves, our strengths and weaknesses, talents and gifts. When we have more information about the different jigsaw puzzle pieces of us, we can understand our own psyches better through the archetypal language of the stars and make more informed decisions.
The purpose of astrology then becomes educational, it becomes a way to look deeper at the karmic playpen we are working within and eventually the goal is to rise above our karmic limitations coded in our charts and translating into our lives through our physical bodies and lives.
In other words, in my opinion, astrology can be used as a tool to help us go with the flow of the universe and our lives and not against it, and when we flow, we learn to grow and when we learn to grow, we live our lives with more freedom and a sense of expansion.