For example, one reason I think free speech is vital is that I want everybody to have a say. Another is that think society works best when we hear from a wide variety of perspectives. However, there are some people who use "free speech" as a reason that they should be allowed to be abusive. Note, for example, the way that Kiwi Farms was waving the free speech banner. You'll see the same thing being done by people who advocate for exterminating Jews and returning Black people to slavery.
In practice, a platform like Twitter has to choose between hosting abusive Nazis and hosting the people who the Nazis would try to drive off the platform. Personally, I am more concerned about Jews feeling safe to speak freely than I am about Nazis wanting to use their free speech to abuse them. So although my 20-year-old self might have been shocked that I am no longer a free-speech absolutist, I am fine with him being shocked, because I have come to value net, long-term practical outcomes more than the isolated ideals that I now see as valuable heuristics, not articles of faith.