Well I may not have personally seen hell or heaven but I know some folks who have. Their experience is worth something. Even if it is anecdotal that doesn’t mean it isn’t real. I could tell you some short stories about a recent trip to Argentina. Just because it is anecdotal doesn’t negate the trip nor what I experienced.
An experience, an anecdote, a trip, a story. Things occurring naturally, not supernatural things.
Heaven and Hell are supernatural assumptions.
Assuming the supernatural, does not mean the supernatural could exist. It cannot just be assumed into existence.
You can put your trust in science but science has been wrong many times...many times. Science in no way means it is always correct nor is it infallible just because it is science.
Science is so successful exactly because the method it uses tries to prove its findings wrong.
Supernatural doesn’t negate existence.
Actually, it does.
Supernatural is supposed to be something
beyond existence.
Beyond existence is not existence.
Not existence, then it doesn't have existence.
Doesn't have existence, then doesn't exist.
Hell is said to be beyond existence so cannot exist.
So when you no longer exist you're supposed to exist

in a place that has no existence.

Ironically enough, supernatural is a natural belief phenomenon, so not even supernatural of itself.