Destiny is not real, in and of itself, it is just one factor in play, in the puzzle of life. Destiny means if you throw something in the sea, it would definitely reach the shore.
Think about it, Lord Ram was destined to become King from the very day he was born, but on the day of his coronation, which was predicted by the astrologers, what happened? His destiny for that day turned out to be something else altogether, and the astrologers were proven wrong. So the timing was not right and he was exiled to the forest for 14 years, otherwise what the astrologers predicted would have actually transpired.
So destiny is just one part of the puzzle, there is also time, space, karma, effort, etc., which all come into play when it comes to the unfolding of events in one’s life.