As I see it, we need first to become clear about the term "destiny." Destiny is related to destination, that is, reaching a certain end goal. That assumes that time is real, which is doubtful. But if you mean "destined purpose" so that pershap we are destined to do certain work over time, then the issue is seen differently.
My own practical approach is to divide "destiny" or "purpose" into two elements, Spirit and Soul. The Spirit element is about Love as genuine non-violent power, living true to who we are and harmlessly to all beings. I believe we will ultimately all do this. Free will is our choice to delay Peace by refusing it for now, as we , for now, prefer things of the ego. at this level, all people face the same issue.
The other aspect is Soul. Here, there are unique lessons, unique pieces of karma to complete. And, as we complete our karma, we become freer and freer. Then we have unique creative gifts to develop and share, unique ways of serving, and a unique population of people animals, or plants or ecosystems to serve.
So free will is the degree to which we choose to see, receive, embrace, and act on our general human destiny of Divine Peace and our specific destiny embodying the journey of learning, love, creativity and service of our soul.