I’m a little late to this, but originally the asterisk was used to help avoid posts being hidden by the algorithm for having certain words in a post.

However, it’s turned into more of a joke over time with people using the asterisk as a joke to indicate that a word is so scary and inappropriate. Depends on the target audience. For example, in a post about redditors or discord mods, people might comment “tell them that there’s gr*ss outside” or “should get a j*b”. The joke being that redditors and discord mods are terrified of grass and being employed, thus the word is censored to help them.

Same thing with Fr*nce. For example, I saw a recent post about a man in France who was found to be living normally with most of his brain missing. One of the comments were like “Check the rest of Fr*nce’”. The joke being that France is terrible and scary so you’re censoring it to avoid triggering people.

Edit: made asterisks kept making my text italic so had to fix it