I find this to be one of the most useless philosophical questions of all times:
1 - Such an answer, to be as such described, would need to be consensual, and thus an "universal truth"
2 - Here would reside the first problem, there exist no "universal truths", since truth is a result of our interpretation of facts
3 - The fact being, that life merely "is"
4 - Such a fact - that life "is" - automatically urges man, due to his nature, to interpret meaning in "it"
5 - So... we would have as an end result, if you would like: man exists because he questions and "projects" onto the object of his/her questions, its meaning... and the object, even though intangible, if so be the case, exists, if not only in the manner that exerts some kind of influence on the person by it imagined, thought, or observed!
In other words, I quote Fernando Pessoa: (