Or that undoes self-censoring like fk or a$$. I mean come on, who thinks that actually "protects" the reader or whyever they do it?

Kind of curious, isn't it? It gets around filters, but I assume that's not what you're talking about.

I imagine some people have psychological aversions to "filthy" words like this; and that seeing such substitute words is less uncomfortable for them. That does, however, beg the question: if the intent is to avoid giving offense, why not avoid the word in the first place?