alt Hacker NewsFor the uninitiated like me:
The manosphere has its own distinct jargon.[31] A central tenet of the manosphere is the concept of the red pill, a metaphor borrowed from the film The Matrix. It concerns awakening men to the supposed reality that men are the oppressed gender in a society dominated by feminism
( From https://en.wikipedia.org/wiki/Manosphere#Jargon, I landed there from https://en.wikipedia.org/wiki/Red_pill_(disambiguation) )
They stole it from other groups online that simply used it to mean "I can see through the bullshit now". It got nothing particularly to do with the manosphere and the grifters in it.