Will there be boobies in heaven?

[Sword of Christ]

Nor has anyone else who managed to provide an account of what comes after...

It's possible that near death, or short term death experiences are accounts of what comes after. We don't actually know so you can believe either way. It isn't necessary to know something for certain fact before you're allowed to believe it.

But still, you go on with people's accounts of this voyage:

So people make stuff up.

Someone has at some point but there is no way to know who made what up and when. But you can make up your own mind it's a free universe.

Why should I assume a particular version is indeed factual and real?

You don't have believe anything it's up to you what you want to believe. There things we know for a fact and things we may or may not know. As long as you understand the distinction and the possibility of being wrong. A lot of atheists/materialists could do with learning that they aren't all knowing gods there tends to be a lot of arrogance and bluster from that end.

No one has ever died and came back

Perhaps one person did, no way way to know though. And of course near death experience if they occurred while the person was in a physical flat-lined state may well count. These are subjective experiences of course and can't really be accessed by science.

... sure NDEs... the "near" part is the kicker

They may occur while the person is actually fully dead and physically/biologically inert though. In which case these are experiences that occur while the person is dead. It's a reversible state of death but they are still dead for those few minutes. In some cases the person enters the process of death from consciousness awakeness so that wouldn't leave any time for a dream or hallucination in an active functioning brain.