Why are there so many b@nned words in direct messages

I got b@nned (cant even type this word normally in this subreddit...) from direct messages 2 times for saying the f slur when chatting with a friend. And now I even got a warning when saying a very normal sentence: ''and what is that supposed to mean'' because my friend send me a video that was in his language. What is wrong with these systems. Please make private conversations normal like every other app. You shouldn't be punished for saying a basic slur, especially when the app is 13+ and a 13 year old will already know these slurs. I just want to react to the videos my friends send me with a honest reaction, and not with fck without a U because that's sooo innapropriate.