Why Not Just Use Word Filters/Replacements?

I was just thinking about the Voat situation and many of the issues facing "free speech" platforms. Besides attracting an audience that tends to shit where they eat I was thinking a good portion of the issues they have stem from a few words. The discussion of free speech and censorship on these sites almost always boils down to a few words. Which reminded me of the time when 4chan decided to create a word filter to replace certain words with "rudy poo" and "the people's champion". It was a fun creative way to skirt some site issues for a time. So why not word filter the words that will get you demonetized and deplatformed, the community will know what the words mean and outsiders seeking to bring down your community would have to do a lot more work to prove intent.