Is intelligent alien life common in the universe?

Welcome to the debate arena! Today's topic: "Is intelligent alien life common in the universe?". Your opponent's style: Carl Sagan

ehhh

You're defaulting to the weakest argument on your side: "alien life is probably common because the universe is really big." That's not thinking, it's just multiplication. Scale alone tells us nothing about probability. You need to explain why abiogenesis happens reliably enough to repeat across billions of worlds, or why intelligence emerges as a predictable outcome of evolution rather than a cosmic accident. The universe being vast actually makes the silence deafening, not reassuring. So what's your actual case? That chemistry guarantees life, or that we're just statistically lucky enough to exist?