Saying "you're not entitled to X" with reference to current laws is disregarding that people are actually arguing against those laws, or about situations where they don't apply. Even when people are talking about the law, some laws are unjust: quoting present law is not an argument about anything except what the law is.
I'd also encourage you to consider that the writers of the US constitution were in favour of free speech generally, and almost certainly would have tried to constitutionally entrench a broader concept of it than they did, if it were practical to do so. The decision to only prevent government censorship is a practical one - government stopping others from censoring was (is) considered outside of the role of the government, or too impractical to actually enforce. That doesn't mean the writers of the constitution thought that other kinds of censorship were ok. They just didn't think rules about them belonged in a document about the US federal government.
Finally, most countries do not have freedom of speech entrenched in their constitutions, but "free speech" is still a phrase in these places, and they are not talking about the US constitution. Free speech has historically been considered an important right in post-enlightenment societies, regardless of legal protections, and regardless of trendy people on the 'right side of history' saying otherwise. The fact that oppressed people are presently somewhat anti-free-speech is due to the unusual situation of them having friends in high places. This is not usually the case, and throwing out the ideal of free speech to the greatest extent permitted by the US constitution does a great disservice to future oppressed people who are unlikely to have the media and tech companies on their side, as well as present oppressed people who have fallen through the cracks because their flavour of oppression isn't currently in vogue.
Not all opinions are equal and they shouldn’t be treated as such. It doesn’t quite work with free will and all.
You voluntarily subscribe on social media though. Nobody is forcing you to hear their noise
There's more to free speech that "you don't go to jail".
In fact historically it wasn't necessarily the state that mostly got you for saying things they don't like. It was the church (a separate thing), "concerned citizen" mobs, and so on...
Losing your job, being deplatformed from platforms where the majority tunes in (and thus being relegated to fringe, not from being unpopular but for what you said), having (privately owned) shops decline to carry your work, being made a pariah, are all parts of free speech.
Some common examples of post-Spanish Inquisition cases:
Novelists like Henry Miller and Burroughs didn't have trouble just with government censorship, but also by private publishing houses that wouldn't carry their books, because "concerned citizens" would bully them if they did.
Punks in 1977 were attached, not by the state, but by right wingers and conservative citizens who didn't like their style.
Parental organizations fought whenever some album they deemed "controversial" was released, from the Sex Pistols, to Jello Biafra to Marilyn Manson (and earlier), and tried (and often managed) to have those albums deplatformed, with major chains refusing to carry their stuff because of threats...
People considered of this or that affiliation would often not be persecuted by the state (at least not directly) but be branded and lose their jobs (even though this had nothing to do with their job performance). This, back in the day, include anything from suspected communist sympathizers to black rights activists, and still does all around the world...
That's what people mean.
Does China putting pressure on the NBA to stop players from saying pro-Hong-Kong-protests things not fall under the gambit of censorship/free speech issues as far as you're concerned?
(Heck, even in terms of the US constitution, public institutions banning some symbols or items have been overruled based on first amendment grounds. So just banning a student from wearing a certain type of t-shirt is also a free speech issue.)
That said, I find weaknesses across the board with conventional arguments and talking points concerning speech.
It really is complicated. And there is considerable previous thought, precedent, and philosophy that's been forgotten or ignored.
NBA's interest in China is at least $500 million and may clear $1 billion. That's consequence-inducing.
https://www.si.com/nba/2019/10/07/daryl-morey-rockets-china-...
Point remains that as a government China has considerable means and impunity at its disposal.
The fact that numerous non-state actors also do is a key extension of free-speech concerns I find poorly addressed. The NBA as a media platform (among its chief roles) is an example. FAANG similarly. There are numerous others.
There's lot's of soft political pressure they can apply, well short of arresting anyone but not to be taken lightly.