I don't think that we are for any "reason", it just so happens that we are here. You could take this a couple of ways if you want
- if there is no grand plan (a la God) then what is the point of life. We may as well just kill ourselves now & get it over with, but I prefer another viewpoint
- if this is all that there is then we don't get any second chances - no heaven, no hell, no redemption... etc - so it is even more important to make the most of what you have - live the best life you can, get the most out of it because this is all that you get forever & ever. Literally life is way too short so enjoy it.
Ultimately I think that the purpose of life is to ensure the survival of it's species - humanity has a problem fitting into this because we accidentally evolved a high degree of self awareness. Think about it, if you are not self aware you will gladly grow, spawn (in one way or another) & then die without any problems. Life has been doing this on Earth for over 3 billion years, it's really only in the last couple of million years that we came along & only in the last 0ne or two hundred thousand years that we have even pondered the meaning of life.
Life goes on unaware of the meaning & totally unaware that there was a question to begin with.
Simple, I know but who said it had to be complicated.
Allan