Of course. Some characters are low-lifes. Characters may be stupid, racists, and murderers. Or worse. People also vomit, pick pimples, defecate, even stick their fingers in their nose then taste it. They also go to the bank, get new tires for the car, and go to church, synagogue, mosque, temple. But you usually don’t read about fictional characters doing any of these things, unless it is integral to the story being told.
Same with profanity. With so much in writing, less is more. With profanity, the less, the more powerful. And as with almost any advice, there are exceptions. For an example of the (over) use of the F word, brilliantly used to depict a great character, watch Julia Garner as Ruth Langmore in the TV series, Ozark.
Here’s a link on the history of profanity going back to classical times.
I’ll end this short blog by sharing some wisdom about the use of a universal vulgarity shared by my writer friend, Jeff.