Keep in mind that, as children, “play” was totally meaningless too. It had no societal benefit, no ultimate effect. We played, it ended, so what was the point?
As conscious beings, our reality is to be conscious. It does not necessarily require a higher moral value, or an ultimate destination. If being aware is all we can truly possess or achieve, then the goal should be to refine our acute appreciation of what life has to offer, and the nature of things, however impermanent — maybe even because they’re impermanent.
Why do this, if everything is transient and perishing? Because. I think you’re brushing up against a meaning of enlightenment here: Being has its own truth, which the wanderings of mind will never fathom.