I'm an old fucker, to me it seems like the tipping point started in 2008, and really started to get bad in 2016.

I was already chatting on online forums in the late 90s, and on slashdot starting around 2000. There was lots of discussion, some of it first, but it was just discussion. Not a lot of politics per se.

In September 2001, al queda attacked the world trade center, the Pentagon, and another plane was flown into the ground. This led to lots of discussion online and a massive increase in political conversations.

In 2003, America went to war in Iraq. This was a generational event, and it fundamentally changed internet conversation. Partisanship really started to show up, in part thanks to George W. Bush's "you're either with us or you're with the terrorists" rhetoric.

At some point along the way, I stopped using slashdot. I tried using kuro5hin for a while, then Digg, and eventually landed on Reddit.

Two fundamental changes that happened in 2008 were the election of Barack Obama, and the Ron Paul revolution. In both cases, internet ground game ended up having an outsided impact on politics. Barack Obama ended up being an internet sensation, and his Democrats got the presidency and both houses of Congress by a wide margin. Ron Paul didn't come close to winning any primaries, but the shadow of this campaign cast a long shadow over the Republican party, arguably leading to the tea party faction taking over the party for a time.

This made everyone perk up in politics. Where a few candidates realized before that this Internet thing could be powerful, 2008 showed that it could fundamentally change the game.

While reddit was highly political in 2008, there were many factions. That's what made it a fun place to be -- there were right wingers, religious people, libertarians, liberals, socialists, and social justice advocates. I think at this point, however, forces started to work to take over the discourse. By 2015, subtle changes had taken place to really make anyone who wasn't part of a specific ideology feel unwelcome, including a differential treatment of different groups. Most brigading subs were handled by admins (by shutting them down), but notably /r/shitredditsays which brigaded "bigoted" comments was allowed to stay up. Powermods were previously a problem on Digg, eventually the same problem seemed to start occurring on Reddit where a small group of mods were controlling hundreds of subreddits.

By the time I left for good, it was clear to me that reddit wasn't anything like the place it used to be. Many subreddits either through social engineering or through bots would see posts that were not part of the mandatory orthodoxy immediately hammered into the dirt. "The downvote button is not an I disagree button" clearly didn't apply anymore. Until that point, I was deleting my account every few months and making a new one because doxxing was a growing problem and I didn't want to have my real life destroyed for having an opinion people disagreed with, but eventually the site lost all value to me since I knew you couldn't have discussions on the discussion site any longer.

The successful election of Donald Trump put everything into hyperdrive. Controlled subreddits became graveyards of dissent, and polarization became total as people picked sides. At that point I no longer returned to reddit in any regard because there was just no point.

The cultures of the different highly polarized sides became quite different, all toxic in their own ways. The left became ridiculously authoritarian to keep outsiders out, the right became ridiculously offensive to keep outsiders out. The fact that there was one website (whatever that website was) meant that you could kinda play for keeps -- take over a website with authoritarian moderation or with extreme offensiveness, and you win that front.

My hope is that the decentralized nature of the fediverse helps. When Lemmy.ml or beehaw go too authoritarian, people can just find something else on the same platform that's more reasonable. If certain websites are too crass and offensive, people can go find something else on the same platform that's more reasonable. In it's built-in diversity, the fediverse is set up so everyone can have their space, and the worst that can happen is someone shunts you out of theirs (but you get to keep yours).

I've found the fediverse actually deradicalized me a lot. There are still people I disagree with, but I get to participate in discussions that remind me that whatever the "other side" is has some good ideas, and also I get to see that I actually disagree with extremists of all kinds. Being exposed to bad ideas doesn't make me agree with them, it helps illustrate how bad they are regardless of source.