Isn't this a relatively censorship-free time compared to, say, the 60s? If I wanted to spread some nonsense, I had to get approval from a publisher or editor or radio or TV station that would allow me to put it out there.

Now, anyone can say anything for all to see, with the occasional purging of public forums. You can't argue that there's no censorship, but I certainly argue that there's much less.

Have we always been proclaiming that free speech is being eroded, or is this merely a product of our time?

Well if you remove the liars ability to broadcast their lies, democracy is improved, isn't it?

Only if you simultaneously make sure that the truth does get heard.