They aren't immeasurable. The reason you think I'm making a different argument to your point is that you're asking for every negative proof. This is never going to provide an answer, as it would be a competition to dispel the imagination.
Hypotheses and positive proofs are slowly answering the question of why we're here. We know that evolution is likely, DNA is irrefutable evidence. We know that it's likely our known universe began with a singularity because of the background microwave radiation accelerating away from a point of origin. We know the field and corresponding particle that gave matter its properties from the particle acceleration tests by CERN.
It becomes a much different question when one is not only seeking answers that fit their beliefs.
I think you're forgetting that the supernatural is but another theory, put forth by humans, to explain our existence. It doesn't earn bonus points for being unobservable. I've seen 0 evidence supporting it, contrary to how many questions particle physics has solved.
I've posited quite the opposite of this. If there are two opposing theories, with one substantiated and one not, then the substantiated one is more likely. For example: you wouldn't say that a chicken's offspring being implanted in an egg by cosmic rays is just as likely as the egg being fertilized before it was laid because the latter is substantiated while the former has yet to have any observable truth.
I'd say 99% is a completely fair probability as the ratio of something to nothing approaches infinity.
I just gave you some? I don't know about you, but humans being able to replicate the exact particle that originated matter is a profound bit of evidence towards the universe not being a product of some higher power to me.