Authenticity online USED to come somewhat naturally by virtue of just... starting communities. The reason was that the web was small, and discovery process was more random - that is, less systematic. As a consequence, you almost couldn't help but start forums or blogs or content platforms with hundreds to low thousands of participants. And because those communities were smaller, you were that much more engaged. You recognized the names of the people posting, and understood their brand. So online authenticity used to exist without having to merely import meatspace directly.
But the interesting thing is that there's still nothing that makes it fundamentally impossible to start a relatively small forum nowadays. And there are plenty of those small communities that still exist! And yet... somehow, that's just not good enough, is it? We are all still constantly complaining about the attention economy and the performative nature of online communication. So what gives?
To me, what this says is that it's not good enough for small-band, high authenticity communication to exist. It also needs to be true that broadband, inauthentic communication NOT exist. The simple truth, I think, is that it annoys us when things we don't like manage to capture lots of attention. When you see something you disagree with gathering momentum, it _grates_. There is something fundamental about that; "get over it" isn't going to solve this.
You saw this happen with Reddit: slowly, the most popular subreddits became bigger and bigger cesspits. People always suggested that the way around this was to just ignore the popular stuff and find smaller subreddits to enjoy. But it just never resonated with people as a solution. Ignoring the popular subreddits as a lost cause feels like putting your head in the sand. Don't bother trying to explain to me that you can't fix discourse all by yourself, or that there's no sense in sweating what the front page of reddit looks like. You're not arguing with me! You're arguing with the millions of people's inner id, who see that front page and twitch a little bit.
I think this might speak to some human need to assert our own view of the world and reject untruths that we've already ourselves debunked. When you see somebody pronouncing an old thing you _used_ to believe, your impulse is to warn that person "oh no, I can see why you'd think that, but it's actually more complicated than that for reasons x, y and z." But imagine that you see somebody drowning in falsity and before you can reach them to disabuse them of their misapprehension, thousands and thousands of people crowd around them, agreeing and cheering! And then, before you can push through the crowd and take the podium, they all disperse into the void. You can't call them all back and explain that they just walked away with the wrong information... they're just.. gone. Gone, carrying the virus of bad ideas out into the aether, now sure to awaken somewhere else, like wack-a-mole. Something about human nature finds this situation insufferable. But the twittersphere is perfectly designed to make it _the only way we communicate_!
To bring it home, I think our need to right wrongs is what doesn't scale. We can't all convince everybody of our own world view, but globally networked, systematically visible communication baits us into doing exactly that. Once pandora's box is opened, we can't ignore the temptation to participate, nor can we ignore the constant insult of participating.