How is it an “unfair” advantage? It’s just an advantage. It’s not like getting a good nights sleep is something that requires an exorbitant amount of money.
Kind of tongue in cheek; parents know the struggle of getting kids to sleep, it takes dedication and effort to not just wait until they decide themselves to go to sleep.
This dedication and effort requires time and patience, and with more kids raised without multiple adults (time is zero sum), that time is missing, and those kids ‘naturally’ decide on much less sleep than they need (because as we all know, the distractions available are amazingly fun).
https://www.healthline.com/health-news/children-lack-of-slee...
Parent advice: Get your kids to sleep, it gives them a huge unfair advantage in school :)
https://news.mit.edu/2019/better-sleep-better-grades-1001