[user104658]

Scientifically proven that less than 7 hours a night regularly for adults results in health issues. Not just "maybe" - definitely. Ranging in severity, of course, some people it's just minor things but can be bigger things like cardiovascular issues, especially as we all get older .

But yeah it has recently been confirmed; there is no "some people get by fine on less". The damage is being done whether you feel it or not.

Obviously this is "over the long term" - some times in life it's unavoidable that you'll get less sleep. Illness, young kids etc. but it's not meant to be permanent.

And I say that without judgement as someone who rarely gets more than 6h sleep a night due to being a carer for a child with disabilities. I am well aware that one day I'll simply wake up and have a stroke or something .