It also depends on what is offered in its place.

We don't debate this enough, because it's invisible to most people.

Free speech in the broadest is exactly about curation, implied approval (proof by authority doesn't work philosophically, but absolutely does work rhetorically and politically), and access to airtime and audiences.

All of those can be bought with money.

To make an obvious point - if you can use money to impose your choices wrt curation etc, speech is no longer free.

This is a completely different meaning to "Talk about this and the government will imprison and/or murder you."

The latter hardly happens to anyone now. The former is absolutely foundational to the media.

There is no "marketplace of ideas" because those with money and political power can always enforce their narratives on those without - and they can do it cleanly, deniably, and effectively without needing to murder or jail dissenters.

They can even do it from behind various front organisations and curated movements, pretending to be scrappy freedom fighters railing against an oppressive mainstream.

Speech isn't free in any genuine sense while that remains true.