You can take it back out even further and ask why a universe in which chemistry is even possible popped up. A single small change and either everything becomes unbelievably heavy and collapses, or everything stays unreasonably light and we never get past hydrogen and helium.
Fun fact: it's very easy to rule out a multiverse theory where travel between universes is possible.
If the multiverse theory is correct, every possible combination of universe is out there. This means there is a universe which formed in exactly the right way such that the citizens all decided to leave their universe and invade our specific one. They formed 10 billion years ago and completely annihilated all matter in our universe.
Since we are still here, either the multiverse is false, or travel between universes is impossible.
If you define "our" universe as a particular set of states aren't there more than one of "ours" or in fact an infinite number of them which are either identical or indistinguishable some of which got invaded and more which didn't?
Only the ones in which we all didn't get murdered are having this conversation.
You're assuming that that particular set of universes is possible. Maybe it hasn't happened because getting them to agree is not scientifically possible.
This reminds me of Stephen Hawking telling John Oliver that the latter dating Charlize Theron is beyond the bounds of scientific possibility in any of the infinite parallel universes.
Fun fact: it's very easy to rule out a multiverse theory where travel between universes is possible.
If the multiverse theory is correct, every possible combination of universe is out there. This means there is a universe which formed in exactly the right way such that the citizens all decided to leave their universe and invade our specific one. They formed 10 billion years ago and completely annihilated all matter in our universe.
Since we are still here, either the multiverse is false, or travel between universes is impossible.