You don't seem to realize that the definition of life is subjective.

It's entirely possible that intelligent aliens exist in some far flung corner of our galaxy, or beyond, that bear absolutely no resemblance to life here on Earth, and would not be included in some definitions of life.

We haven't come across them yet, just as we haven't come across genuine artifical intelligence yet. When and if we do, in my view the definition of life should be updated.

http://cherenkov-radiation.blogspot.com