I've seen a lot of sites come and go, some of which are still around, but the biggest change I saw was the end to MSN Groups...And boy, that was definitely something. Lost a lot of people I used to talk with often, and a whole host of information that is just gone.
However, having seen what became of reddit...well, I'm not too sad to say goodbye to it. Another (be it Lemmy, kbin, mastodon, what have you) will come around...At least I hope the information keeps being rewrit/improved upon, heh.
(Note: I'm not exactly sure if Article was the best choice to post this, but meh, it's what I used).