For some people technology causes them to use expletives. In my case it used to be that technology would get in the way of being able to truly express myself. Most spell checkers allow you to add words to its vocabulary. This is not only helpful with raging expletives it also allows for new words. Words that have spread through the general population but are not yet in a dictionary. Unfortunately some may eventually make it.

In general I am not a person that swears frequently.
My friends can attest to it and I live alone so there are no potential witnesses at home.

I am the same with writing but every once in a while a writer or specifically a writers character absolutely has to express some emotions that can only be conveyed properly with a streak of blue.

Case in point.
Gangster, mob or just crime stories in general .
There are often scenes in crime related movies where lack of swear words just seems unrealistic and even phony . It would be just as unrealistic if Wally and the Beaver ¹. entered the screen with a flurry of expletives. Your jaw would drop as well as anything you were carrying.

Upon finding a horse head in my bed I would personally scream holy shit or WTF or some string of similarly emotive words. It sounds much more realistic than a Ned Flanders response “Oh fiddlesticks my sheets are ruined.”

In the middle of a gun fight it is much more realistic to scream “I’m going to bust a cap in your expletive ass” than “ I am going to fill your derrière with hot lead.”
Some people may get excited at that prospect but again it would probably elicit snickers and snickers are positively not allowed in a shootout.

When a loan shark has the fingers of a debtor broken its perfectly acceptable, neigh almost required, for the debtor to cuss to the high heavens. Responses such as “that’s going leave a mark” may be hysterical but certainly doesn’t belong in a drama.

There are apps out there that contain profanity filters which will scan text and if a word in it’s naughty list pops up it will either allow the first letter and replace the rest with the usual #$@! symbols or it will replace the rest with “((expletive), (vulgarity) … etc). The latter is somewhat classier but condescending and takes the fun out of trying to figure out what the word is.

So by all means have your low life criminals swear up a blue streak because, well, because they are low life’s. If they tend to populate higher social strata try to avoid the cliche of any dialogue requiring clenched teeth.