When I was a teen, self-deprecating humor was used to defuse building tension. Today it is used as a weapon.
This is because we live in a socio-political environment that favors the appearance of being a victim without actually being one. Actually being a victim is a miserable condition that favors no one.
Very few people have the sense of self to maintain and project their confidence after being victimized. This is why it is advantageous to be a victim by appearances only.
A master of social media can manipulate an online interaction so they can use self-deprecating humor to disarm a person and gain the appreciation of those watching.