Because the universe is expanding. If it were finite it wouldn’t be able to expand. Emptiness is still “something”. If we were “at the edge of the universe”, we could still go further from the center, there would just be nothing for as far as we can perceive, maybe even infinitely, but then, we would be there. That makes it “a place”.
If nothing is there then how can you say something exists?
Because the universe is expanding. If it were finite it wouldn’t be able to expand. Emptiness is still “something”. If we were “at the edge of the universe”, we could still go further from the center, there would just be nothing for as far as we can perceive, maybe even infinitely, but then, we would be there. That makes it “a place”.