I don't think it did either. If anything, mainstream internet adoption created some awesome opportunities for getting away with bad behavior. Remember that Google's mission used to be to "not be evil"? That clearly went out of the window; I thought that we've discussed that earlier this year somewhere on SN but I can't seem to find it.

It really depends on the communities and when, because these rise and fall. For example, to me r/bitcoin was okay until the whole Bitcoin Unlimited drama; I unsubscribed at some point after that because the toxicity was becoming annoying. It was cool that you could just ask nullc or jgarzik something though, and it looks like you can still do that there today. I've left Reddit fully right before the WSB hype though, it didn't feel like "home" anymore. Whenever I take the trouble of opening tor browser to read reddit, I still feel it's no longer the cool place it used to be; more degenerate, less intelligent, though sometimes funny.

That's part of it, but it takes more than just something new, it takes something better. And alternatives can also be better because of enshittification of the last best platform, which I kind of feel happened to Reddit.

For me personally, SN replaces Reddit, because it's a better community-home for me than Reddit has been; there's many nice people here. I'm not sure if this is 100% thanks to the model, perhaps it's also that founder attitude (thx 4 awesome, @k00b) attracts likeminded people and you can feel that in the vibe here. However, that too may change over time, but for now, it's great.