Besides being an appeal to authority, this is directly addressed in the piece: https://guzey.com/books/why-we-sleep/#appendix-common-object...

> ...it was read by hundreds of psychologists and neuroscientists who – I believe – also failed to find any serious issues [...] Some of the scientists wrote to me directly [including] a sleep scientist with >50 h-index who studied sleep for more than 40 years