if you blackpill them at an early age then even 7/10 chadlites will rope before they even get to age 18 lol
the whole blackpill ideology is completely incompatible with normal development.
telling an impressionable kid that his life is fucking over and everything is hopeless will completely fuck him up and throw him into deep depression, from which he will possibly never escape again.
humans NEED hope. it is absolutely essential. without hope there is no reason to get up in the morning, no reason to do anything at all, no reason to even live. taking that away from someone, especially a kid, is straight up abusive and evil.
in my opinion, blackpill knowledge should be reserved for fully grown adult men, and that means age 21 minimum. before that age you simply can not say with confidence that it is actually over for you, unless you are the truest of trucels with brutal facial deformities.