Without Prejudice. Why does anything matter? Ah very good topic. My answer to this question is informed by some existential philosophers, especially Heidegger, Nietzsche, and Sartre.
So, in one sense you are kind of right. If we take a mental step back and evaluate life from a 3rd person view, we do not know if there is any meaning to human life, and it doesn't seem like there is.
However, from a first-person point of view, there is plenty of meaning. I enjoy nature, for example. Everything I do is meaningful if it allows me to do more of the things i enjoy doing. For example, I detest working at my current job, but it is meaningful because it supports me while i go to college to do something I will enjoy.
I think the whole "life is meaningless" thing comes from the way society teaches us to evaluate things. If something doesn't serve some goal, it's useless. For example, a lumberjack may be conditioned to see a tree as just material for building a house, and if it isn't good house-building wood, it's useless. Yet, this type of thinking is shallow. When we think this way, we lose our ability to connect to nature in a fundamental way, a way that is best expressed by poetry.
"life is meaningless" arises if we only tend to the rational side of human nature. We have learned that we must constantly have some justification for everything, but why do we need to justify what we enjoy? Why do i enjoy video games? because it's fun. Why should i beleive its fun? Who cares? it just is. Not to say that inquiry into why cant be useful in some contexts, but in others it can ruin the experiential side of human existence. To assume i must have a reason for everything is pathological and is a sign of an anxiety disorder, not intelligence. Rationality is not the only part of human experience.
So, in summary, is life objectively meaningless? I think so. However, this is an inauthentic way of living because it prioritizes society's way of valuing things over my own subjective experience. I do not live outside of life, looking in. I live inside of life where i find plenty of meaning if i tend to my whole expereince of being human, and not overuse my rational capabilities to reduce my experience to nothing.