It was around the 2016 election that things started to change. Before that, there was still a mentality of open and genuine discourse in most subs. But after the election that started to die, people started realizing bots and alt-righters had no interest in open discourse, on the contrary they would see to abuse such channels as a platform for their hate, and would use such hate and anger in an attempt to shape and suppress discussions. This forced the community to become far more jaded and less open, realizing just how vulnerable the community was to radicalization and firehouse misinformation.
On the early internet, we all had this vision that free access to information would free everyone, that unlimited information could only do good. Most of those people now understand how nieve we were, unlimited information means unlimited disinformation, and that organizations would always see to weaponize information the way they weaponize everything else. We are in a different internet age, now.
While other browsers technically exist, it is foolish to think that web browsers are a thriving diverse ecosystem right now, when 74% of all web-browsing is done using a Chrome-based browser. With their influence, if Google decided to start forcing changes on how websites function on a technical level, they could absolutely do that with little to stop it;- what are websites going to do, alienate a supermajority of their users?- And that is why people are so worried about things like Threads, because once a single company has supermajority control of a market, they can use that control as a weapon to get what they want.
I say this as an avid Firefox user: Firefox is niche. And the only reason Safari has 20% is because it is integrated with apple products, if it weren’t for that, Chrome and Chrome-reskins would effectively be the only option.