There are two eras when humans had access to equalizing weapons. One was ancient Greece, where the phalanx was the height of military technology at the time. The second was colonial America, where the Kentucky long riffle was the best weapon available. Both eras were societies where the average man could afford the highest military technology available. They are also the eras that saw the emergence of democracy.
Equal weapons = equal(ish) society.
Birth control freed women from the need for chastity until marriage. Unsurprisingly, the sexual revolution occurred. Now birth rates have collapsed. Groups that have sufficient religious social technology may escape this fate.
Educated women have less children than uneducated women. Male dominated societies educate women less than egalitarian ones. Again unsurprisingly, the world is male dominated. Only a religion that got feminists to breed could end patriarchy, but reality is the last thing women care about.
Nuclear bombs prevented democracy from destroying itself in another World War.
The printing press and the Renaissance.
Movable type and The Enlightenment.
The cotton gin and slavery.
The internet and the alt-right.
Metal armour and feudalism.
Blockchain and ?
CRISPR/Cas9 and ?
Memory sharing technology and ?
AI and ?