You can still say whatever you want online. You just can't guarantee an audience, but that was _never_ the case.
This is definitely not true anymore, but if I cite examples I will as always get flagged by people assuming I support said people/communities.
The age of being able to say whatever you like online is dead when your ability to even host your own site can be removed.
You can say whatever you want on servers you control, just as you always could.
You can't post obscene or extremist content on other people's mainstream platforms, but that's always been the case. Reddit / Twitter / etc are really no different from AOL / CompuServe / etc decades ago in this respect. The difference is that the former are now orders of magnitude larger than the latter ever were, so it feels more painful to give those audiences up.
It's a cliché, but you're not entitled to an audience, and you're certainly not entitled to Reddit's or Twitter's audience, particularly if you get in the way of their corporate aims of serving mind-numbing ads over blandly inoffensive content to placid masses. You can now, as you could always, try to build your own audience. It won't be easy, but it never has been.
Increasingly not true, because you can never control all the services you have to use. Servers are one thing, but you still have to rely on ISPs, cert providers, payment processors, and all that other good stuff.
> You can now, as you could always, try to build your own audience
I'm not speaking of Reddit or Twitter, I'm talking about a fairly controversial website, Kiwifarms. That site is proof enough of what I'm claiming.
The internet isn't what it once was and the "create your own" argument ignores the realities of keeping a site online and accessible.
If it's political, you can still post it to alt.politics on usenet and not have any issues with any central authority.
The past few years have highlighted some of the suboptimal machinations of our society, like collusion between government and media to silence domain experts who don't agree with a dominant political narrative[1].
The ethos of the internet is that it's a place where you can say whatever you want--the corollary is that I should be able to read whatever I want if it's being said. The relationship between me and people speaking is being manipulated, so, in that sense the ethos of free speech and the internet is broken.
The conclusion is that, no, in fact, you can't say whatever you want online. Saying that you can't guarantee an audience (without more context) makes your statement seem pejorative, as though the speaker feels entitled to an audience. The GP alludes to the free exchange of ideas, which your statement seems to ignore.
According to whom? There are plenty of ways that has never been the case. In historical terms, its precedent was in enabling covert comms across large distances. In cultural terms, arguably its ethos is to facilitate the operation of the economy. In technical terms, its ethos is the segmentation and transmission of data. Insofar as you can even reasonably ascribe an "ethos" to machinery, in what avenue do you see this ethos of extreme freedom of speech? Because it sounds like you're saying a promise was broken that was never made.