For me, it's an issue of scale. Your friend is a single person (or family). Twitter is a gigantic, faceless corporation (okay, Elon Musk makes it less faceless, but you know what I mean) that tries to cater to everyone—in effect, it tries to be a commons. Can we consider it one? Should we? Should we make a law that says once a social media company gets to a certain size, it can't censor anything anymore if that content is legal?
I'm generally against additional regulation. I don't think, for instance, a small pro-life forum should be forced to allow pro-choice people to spew vitriol, nor vice versa. I'm hesitant to say the same for a giant company like Twitter or Facebook. There, I think it might be more appropriate to have comprehensive filtering and self-moderation tools vs. shutting people out completely (assuming their behavior is legal).
My statements, while I myself do not necessarily agree with them, are what I view as possible when operating within the current legal framework our government has built for these private companies.
To me, if the government wants to hold a private company to the standard of a public service, then that private company must fully, legally, and entirely become (somewhat) a public service. I view that as becoming a service similar to the United States Post Office.
It's allowed to continue to operate as a company but has to comply with government regulations (whatever those may be). That also means that its goal is not profit generation. It can still charge users for certain services if it wishes but is no longer able to sell user data, and it must remain revenue-neutral.
If a friend invited me to their house I can start calling their wife a fat cow and tell them how ugly I think their children are. It doesn't mean they have to put up with it or accept that sort of speech on their private property. That doesn't mean he censored me or inhibited my freedom of speech.