Some context would've been nice! "for humans", I assume you mean. This strikes me as not a good question, akin to Kent Brockman/Smartline's "Religion: Which is

Some context would've been nice! "for humans", I assume you mean. This strikes me as not a good question, akin to Kent Brockman/Smartline's "Religion: Which is the one true faith?" Life doesn't have "a" meaning, assuming by "all about" you mean something in that ballpark. Meaning is always meaning -for-someone. Or maybe you mean, what is most important. That too seems a matter of some person's values.