Near-Death-Experiences are not for no reason called not Death-Experiences, but merely
Near-Death-Experiences.
There now is a huge empirical observation database of , or literature on, NDEs, what they look like in different cultures. There is a general pattern: the experiences of levitating over one's own body, travelling through a tunnel, sometimes the tunnel already being of light, or a light waiting at the end of the tunnel. There is a culture-specific component: people in india tend to see visualizations of religious gods and symbols common in India, Westerners tend to see visualizations of Jesus and have associations with Western cultural elements. That is the main pattern. This main pattern does not point at anything beyond culture-specific contexts, or general physical conditions of being near to death, although they include sometimes perplexing events like beign able to quote days later what people have said in another room since one levitating alter ego was flying into the other oomand overheard that conversation, and witnesses in reality later indeed confirm it. The levitating phenomenon in itself attracts great interest, of course. The quality of the soothign effect of the light does as well. But both may be two very different things, maybe. The levitation thing may hint at unknown skills the human mind is capable of (there are rumours ab out Lamas in Tibet who were able to walk through solid walls, now compare that with views of modern nuclear and quantum physics: empty space and all that...), the soothing light may be comptrabale to the tranqulization effect that blocks the recognition of pain in the brain in case of beign seriously injured in case of a shockingly quick happening accident.
That any of that, incuding the light at the end of the tunnel, is an objective description of the state of being dead, is pure, unneeded speculation. We know however, that dying is a process, and its true stadiums and duration is not fully understood in mdedicine, the alteraiton of the death criterion in the pasdt deacdes is not owed to insight into death, but progresses made in tranbsplantaiton medicine that demanded people whose organs are to be taken are not as dead anymore as they before were allowed to be in order to call them "dead" indeed. Last years however showed medicine that dying may be more complex than we have once thought in Western tradition (remember I brought this arument already in the tghread about organs donating ?

, remember also that other cultures and traditions often do not share the former simplified modern Western view on death ) The Bardo Thödol however describes, if I recall it correctly (I am not certain anymore) 49 phases of dying, phases of passing through death. Shamans sometimes see death as a voyage.
My
guts feeling tells me that in the West we see it quite wrong, simplified, and subordinated to the needs and demands of modern medicine. But that is just my believing. I will not base a serious argument on that belief.
Lets keep speculation and observation separate. And I say that as somebody who has had strange, NDE-like experiences twice himself, during meditation. Yes, it was reassuring, yes it was not unpleasant, yes it was extraordinary. Still I forbid myself to take them beyond the point where one indeed is fully "dead". What have they done for me? A soothing on my fear of life as well as my fear of dying, else it is the same life with its same problems that waited for me once I was done with those experiences, and them were done with me. A gain for me, yes, but nothing that shakes the Earth or changed everything right down to the fundaments. Observation is this, speculation is that. Two different things. Keep it separate. Quite some researchers would argue for example that the body may have its neural and chemical tricks to make the in principle terrifying expoerience of dying a more relaxed one. I know pro-NDE-speakers have some arguments, some cases that contradict this medical view (yes, I mentioned that - indirectly at last - as well in that organ-donation thread). Again: observation, speculation. We do not know for sure. Believing is not knowing.
I think being sober and as rational as possible when thinking on all this, is like a lifeline. Its easy to get lost in all those dwelling fantasies and tempting, colourful images. Be Vulcan!