I’ve never had the experience of seeing young people refrain from using curse words. It’s usually as people grow up they see it as an immature way to communicate. I personally use them a lot, but in formal settings I certainly don’t. Some people simply don’t turn the switch on and off and elect not to use them so much. I don’t think that’s such a bad thing even if it’s not how I operate. It’s up to each of us how we want to communicate, so frankly, I just don’t concern myself with it.
As for people self censoring online, I have seen that since my old messageboard days when I was a kid. “You can curse on the Internet“ is a pretty old meme. Literally decades.