If this is true, then why are there such extreme consequences to not sleeping for extended periods in mammals ? Without REM sleep (deep sleep does not work by

If this is true, then why are there such extreme consequences to not sleeping for extended periods in mammals ? Without REM sleep (deep sleep does not work by itself), you lose control of your emotions in 2 days at most. You go insane between 1 and 2 weeks (mania, depression, and likely quick switches between those 2), and your body will physically shut down and die a week or so after that. (note that in humans it hasn't been well established that death occurs, for obvious reasons. In mice, however, it's well studied and accepted. No sleep for ~10 days, half of the mice just die). This seems to be a bit at odds with the idea that it's just a brain warming technique. https://www.healthline.com/health/sleep-deprivation/effects-on-body#1 https://www.healthline.com/health/sleep-deprivation/effects-... https://www.livescience.com/52592-spooky-effects-sleep-deprivation.html https://www.livescience.com/52592-spooky-effects-sleep-depri...