Well, I don't care about your religious beliefs, or lack thereof, to be honest. And I'm not about to give you a lecture on spirituality because I'm a sinful person and would consider it hypocrisy. But I'm sure even some atheists and liberals believe in that so called 'supernatural crap'.
The existence of supernatural beings in unproven so far, no question about it, but that doesn't mean the phenomena doesn't exist. We simply lack sufficient knowledge at this stage.
Virus, bacteria, dark energy, big bang theory, black holes, spherical earth and similar other mechanics were merely conceptual, a "folklore" or perhaps a fairy tale back in the days but now these are scientifically proven facts.
The Wright Brothers were often trolled when they decided to build a 'flying machine'. And now, we have supersonic jets that can circumnavigate the earth in a matter of hours, not years.
Moving on, the literal meanings of the word "Jin" is 'invisible'. Quran states, If I'm not mistaken, that these beings reside in 'آسمان'.
Now, what exactly does Quran mean by that? Does it mean they live in atmospheric air spheres above the earth's crust?
That might be true but I personally don't think so. Quran also sometimes refer to the universe as "sky", if I'm not mistaken, and I believe these beings reside in a 'parallel universe' and since Jin is an ancient race that's much older than us, I think they're scientifically advanced enough to visit our universe via portals; interlinking theirs and ours universe.
Keep in mind that parallel universe and portals are mathematically proven facts.
And the thing about mathematics is:
"Politics, poetry and promises can lie. Numbers are as close as we can get to the handwriting of God."
So there should be no doubt about their existence; given the immaculate precision of mathematics.
Anyhow, Allah knows best...