It should be noted that Matthew Walker, in his book, acts as a scientifically unrigorous advocate and gets a lot wrong. I agree with the general message "many people need more sleep than they get, this is a problem, we should take this seriously and accommodate them"; but one must also be certain of one's facts. See "Matthew Walker's "Why We Sleep" Is Riddled with Scientific and Factual Errors": https://guzey.com/books/why-we-sleep/

Prior discussion: https://news.ycombinator.com/item?id=21546850