I think your thesis is inelegantly expressed. By whom or by what are we “meant” to do anything? Nor do we “come here’’ to “do” anything. We’re born, we grow, hopefully while learning what we’re good at, and we live as best we can within the society we find ourselves in. Many people, because of parental neglect or economic or educational disadvantage, never get a chance to learn what they’re good at. Some others, through parental or economic privilege, find what they’re good at and make a life for themselves doing it, or they do what they love, simply because their privilege enables them to (Florence Foster Jenkins comes to mind). I agree with you that probably the most satisfying life comes from learning what one does well and then doing it, but for many people that’s not as easy as you make it out to be.