+1 to Narz and Snowgerry on the Internet not being a great substitute for in-real-life experiences. Not that it's all doom and gloom - I've read some insightful things online, just as I have in magazines. And you do get to know at least a side of people whom you interact with regularly... which is most of the people on this thread. You know, I wonder, "when is choxorn going to post the next chapter of The Conquests? does he still play Civ or is he out surfing in Hawaii all the time?" But while people may not be putting on airs here as they may be on social media, you also don't really get to know people as deeply as in real life. You don't sit down with a CFC member in your living room at 2 AM on New Year's Day, after everyone else has left, and talk about how they've gained perspective on their failed marriage that ended a few years ago.
I agree with Farm Boy, Discord doesn't have a good interface. I remember trying to figure out how to video chat with it with friends the first time, when you just want to chat, not be part of a Discord "server", and it was not nearly as intuitive as adding each other on an AIM buddy list. I still have to use Discord in two separate browsers because half the servers I joined were with one e-mail, and half with another, and I can't just sign in to them separately in separate tabs. IRC, I can join #fiftychat and whatever all else I want with a fair amount more ease, though sadly it appears most of #fiftychat decided to migrate to Discord. I still log into #fiftychat occasionally though, despite never having really been a regular there.
Likes... mixed feelings. The downside I see is that it's a minimal-effort way of providing positive reinforcement, that can be chosen in place of more thoughtful feedback. I have occasionally dabbled in the Stories & Tales forum. Before we had Likes, if you thought something was fun and you wanted to provide encouraging feedback, you had to write something. Now, you can just press "Like" and that's it. As a writer, guess which one is more encouraging? Something that is written out. Doesn't have to be long, but a quote of a section and comment of, "I loved that joke. Keep it up!" means more than a "Like".
Reputation, I'm happy not to have it here. You learn who the regulars are. We all know Kyriakos is one of the city graphics legends, at least if we hang out in the Civ3 forums. The_J posts some interesting stuff to the front page; Fippy regularly participates in Civ4 discussions. There's no reason to feel inferior or superior because someone has more reputation currency than you do.
I have been on a forum where you could send a comment when you gave reputation, which could be a way of saying, "thanks for that Civ IV beginner help guide", for example, without having to bump an old thread just to say it. That could be kind of nice, kind of like Hygro was saying. But I'm not sure it would be worth having reputation currency displayed publicly.
Reddit kind of also leans towards the Facebook/other social media thing of "share what just got posted but not so much older things." It used to just archive any post more than 6 months old, preventing any future participation, and plenty of subreddits still do that, and even aside from that most active threads you'll find on the site are less than a day old, with maybe the odd exception of a big enough topic getting some discussion for a few days or an older post that suddenly becomes relevant again.
It also is definitely not all that great at discoverability, reddit's search engine is legendarily ineffective at actually finding anything except maybe the names of subreddits, and that's if you already basically know what you're looking for.
Ehhhhh... I don't actually post on Reddit (decided not to take the chance of getting addicted to it in college, I was already posting to CFC often enough), and mostly only read it when I find links to it from search engines, maybe if it's a Paradox or Factorio Reddit that I happen across, I'll scroll through a bit and see what the latest is. But locking threads after a set amount of time, regardless of content, is my forum pet peeve. It reminds me of
https://xkcd.com/979/ . If someone posted a question in 2003, and I run into the same thing in 2022, I should be able to reply to the thread from 2003 with new information for the benefit of anyone else who comes across it in the future.
From what I have seen though, I agree. The "Card" view (now the default) instead of "Classic" seems to make it worse, too, by making only about 3 things show up without scrolling. And what others have said about popularity impacting the sort order.