Either everything matters, or nothing matters. Choose one, and follow the resulting consequences.
Like I'm just trying to figure out if you're actually trying to say something meaningful or just saying something vague and abstract to try and sound "deep".
But it's just wordplay. Things DO matter to me. I can care about the fate of my descendents many centuries hence; or the fate of human civilisation in a few millennia. So what if human civilisation (or any biological life of Earth origin) might not survive after a billion years and nothing "ultimately" matters?
Besides, the way most human religions try to instantiate this "ultimate mattering" seems fairly horrid to me.