Arguing for a position of non-belief is very different from trying to prove a null hypothesis. I don’t believe there’s a bison in your kitchen but neither you nor I can prove that. See the difference?
Yes and I can’t prove there’s life on other planets. But then people don’t generally jump to the conclusion that there is none, based solely on the lack of evidence. But they’ll often do the same about the existence of God, and claim that’s science.