No one is arguing that lack of sleep isn't detrimental. Everyone knows this from personal experience. But fear-mongering about long term effects is unsupported

No one is arguing that lack of sleep isn't detrimental. Everyone knows this from personal experience. But fear-mongering about long term effects is unsupported unless you're talking about clinically rare levels of chronic sleep deprivation. There are some studies that show increased cancer risk for moderately reduced sleep, and some that show no increased risk. Likewise with neurodegenerative diseases and other issues. The anxiety created by these weak studies might be worse than the effects of losing sleep that an overwhelming majority of people reading about them will experience.