If people are hallucinating in extremis it would be utterly expected that they would tend to bring the same human perceptions and assumptions to the experience.
It also isn’t quite true that “everyone” has the “same” experiences. If a Christian has an NDE it will tend to involve things they expect from the Christian teachings on heaven. If it is a Muslim or a Buddhist or whatever then they will have experiences more congruent with their expectations. If the person has angst about hell, they may find a lake of fire at the other end of the “tunnel” rather than streets of gold. And so forth. People tend to skim over these inconvenient narratives and cherry pick what confirms their personal biases.
Many years ago, up through high school basically, my stepson was very intrigued by ghost hunting shows on TV. We took him to a local ghost hunt as a high school graduation gift and I noticed a phenomenon similar to the above. The people attending were from a variety of backgrounds and beliefs. They were mostly Christians, but a few spiritualists, and a few new agers, and a conspiracy theorist type. I noticed that they tended to interpret supposedly supernatural communications just as they wished. Christians saw the civil war-era “ghosts” as angels or demons or people communicating from the Christian afterlife. Spiritualists saw it as simply “the dead” and tended to put more stock in the notion that they are “stuck” in a location and unable to “move on”. New age types thought they were definitely angelic beings from some more vague “beyond” than the Christian heaven. The conspiracist wondered if it was telepathic communication from space aliens. All seemed equally convinced that their experiences were confirming their assumptions.
As an atheist I put what I observed down to the ideomotor effect, and I like to think it is the most reality-based hypothesis among those given. It was really just entertainment to me – entertainment that I wasn’t super eager to suspend disbelief for, either.
I also noted that a lot of emphasis was put on being as “open” (credulous, really) as possible, lest there not be an environment conducive to spirits wanting to communicate. That sort of circular reasoning is also common with NDEs and other personal subjective experiences attributed to the supernatural. It suppresses skeptical thoughts or doubts about things being discussed and of course along with that it must always be night, it must be dark and in a suitably “creepy” old building, etc. That is all about atmospherics and mood and vibes.
NDEs are experienced in great distress and peril and so there’s a distinct “vibe” to that as well.