TempleOS - a very gifted individual made his own OS from scratch by himself but was thwarted by his own schizophrenia and delusions of persecusion. He was also incredibly racist. Ultimately though it's very sad story seeing him lose his grip on reality thinking government agencies were after him and he was a prophet doing God's work. It's a decade long saga, he ended up homeless for a long while and died a few years ago.
John McAffee - talking about delusional tech guys, this one takes it to the highest level. This guy travelled the world running from the u.s. govt for tax evasion, won a game of russian roulette through quantum immortality (debatable), killed his neighbor for poisoning his dog(allegedly), and was an avid crypto enthusiast. He was found dead in a spanish prison right before he could be brought back to his homeland. It was declared a suicide but many people don't believe that.
Sudo
LordDespair
NotTheOnlyGamer
stackPeek