what is a "performative profanity"? A profanity which only goal is to be performed, said out loud? What other goals does a profanity have? I guess to hurt feelings of another person?

Basically to get the attention of others and distinguish oneself from the stiff formality of previous generations. It's a very common trope in the titles of self-help books written by millennials:

https://www.reddit.com/r/starterpacks/comments/ceecki/book_t...

Fucking performative fucking profanity is fucking gratuitous and is fucking clearly only fucking there so you fucking know I fucking smoke fucking Camel Lights. It’s not fucking musical. It doesn’t fucking enhance the fucking thought or it’s the wrong fucking emotional fucking register for the fucking material. It’s just fucking there.