Until this point, I have just spoken of purposes in mankind. This theory works for everything else, too. The Human race has a purpose in the context of earth, the earth has a purpose in the context of the universe, etc. Fate has often been liked to a tapestry, so that's what I'll do now. The purposes all link up and cross.
Mankind forms a section of the tapestry, other things form other sections that link to our section.
There are lots of things people do in their life that has nothing to do with Fate. This had no real effect on my life, nor did it affect anyone else's life as far as I know. Fate had nothing to do with it. There are many other things, perhaps more significant, that Fate has nothing to do with that don't affect the world as a whole. Fate only meddles in a very few things, that may be insignificant to someone's life, but may be important to mankind.