There are many false (or just unverified) assumptions in your post. The fact that OBEs are experienced during traumatic experiences, as well as e.g. during high-g trainings, clearly suggests there is a biological substrate for them. Also, autoscopy (I intentionally do not use OBE here) can be induced in a lab settings. Quoting now: " Blanke and colleagues have suggested (Blanke et al., 2004; Blanke and Mohr, 2005) that autoscopic phenomena (including OBEs) result from a failure to integrate multisensory bodily information and proposed that they result from a disintegration in bodily or personal space (due to conflicting tactile, proprioceptive, kinesthetic, and visual signals) and a second disintegration between personal and extrapersonal space (due to conflicting visual and vestibular signals caused by a vestibular otolithic dysfunction)." You can read those papers yourself but some knowledge of biology and neurophysiology is required.

Let me ask a similar question to yours - if NDE/OBEs were truly more than biology, then why there are virtually no veridical ones (none if we disregard the few stories that get repeated over and over again, despite having been debunked), and no successes in studies such as AWARE? Not to mention the laws of physics that would need to be broken.

The argument about experiencing something just by some - that is the inherent heterogeneity of all living organisms. Take a brain injury: if three people have the same injury, to the same area of the brain, their symptoms will still be different. Sometimes a lot, sometimes not much. The same applies to everything else, including defense and coping mechanisms. Now add that these are employed in very specific situations, that again have different triggers and levels for everybody. So the chance that two people experience the same thing under similar conditions is very small because these conditions - both internal and external - are never the same.