At least in the US many words and opinions have been off-limits for a hundred years or more. Death threats are the obvious one, but various types of political or religious views have been off limits (which specific ones has varied of course). In the jim crow south you definitely would get beaten or worse if you espoused views of racial equality, and communist/socialist politics have at various points been enough to get you fired and blacklisted in many industries (still are, sometimes).
I mean, just 7 years after the Bill of Rights and First Amendment in 1791 were ratified, came the Sedition Act of 1798, which was a law, passed by Federalist Congress, prohibiting certain kinds of speech critical of the government. You might notice this being a thing the First Amendment said was precisely off limits. Didn't matter.
Free speech in the US has practically never been principled in support of those marginalized, but a tool for the wealthy and rich to maintain power.
This is not a criticism, just an observation of where we're at and how dramatically attitudes have shifted.