That's an example of a tautology. Tautologies usually aren't well regarded as a means of explanation. The truth they convey is considered trivial. Nevertheless, there is something of a deeper truth conveyed in some of them as well. I suppose many things have been written that purport to explain life, but my sense is they all fall short of the mark.
Life simply is.
Now, this is true both for the physical and biological processes we've come to term as life, and for the thoughts, emotions and events that make up the description of our existense we term life. This is unsatisfactory to many of us. It's been unsatisfactory to me. In many ways, I'm still unhappy with it, though I'm learning to accept it. One source of this unhappiness is, as is often the case with unhappiness, ignorance.