A thought experiment. I'm not sure that I believe this, but I put it out for your consideration.
That which lives is that which opposes the second law of thermodynamics. Life is the balancing counterweight to the second law.
Creatures remain alive, instead of dissipating. Further, various creatures impose order on the world, where the non-living merely degenerates. Beavers create dams. All mortal living organisms reproduce and impose their pattern of structure upon the matter which makes up their forms, in the next generation as in the current.
Certainly living creatures can be destructive, or their acts can both impose order in some areas while increasing entropy in others. But I argue that while the non-living forces of the universe can temporarily reduce entropy (gravity collapsing material into a star), it is life that has the potential to knowingly arrange things so that entropy remains low, or is reduced further.
There is a lot to say about the topic of balance, which I won't go into here. But I'll posit that perhaps the purpose of life is to bring balance, which predominantly means acting to reduce entropy.
In the longer term, this might mean acting to prevent the expansion/explosion/cooling of our sun, by deriving the technology to pump in interstellar hydrogen and later extracting fusion products to keep it from growing too massive. In the even longer term, to prevent the heat-death of the universe; perhaps by persisting all suns, perhaps by figuring out how to use matter/energy to construct new suns, new galaxies, out of the surrounding matter, while we still have energy with which to do so, to create a self-sustaining source of energy to replicate this feat.
We might not yet be smart enough to do this. Humans might never be smart enough. That beavers can create dams, and have done for a very long time, did not lead to beavers creating cities, learnable languages, writing, the arts and sciences (for the meta of dam creation) and more. But perhaps we will evolve to be capable of doing what I posit above. If not us, then some other species. If not from our planet, then from some other.
What if the purpose of life is to ensure that the universe continues to exist in roughly the form in which we now know it?
-The Pensive Troll