In Addition to what Eagle Pursuit said, to me personally it's the lack of Discussions that I'm interested in. Most Discussions around here lately involve the monthly Challenges (which I couldn't care less about), Millennia (which I'm not interested in), and casual stuff like Funny Screenshots or Lego Wonders, which aren't exactly stuff for discussion (or at least, not lengthy and detailed ones).
What I find interesting, is that People love discussions (especially about new Civs/Leaders) and are quite active when the Game is receiving new Content and Updates, but only for official content/updates. Most People here play on PC, so I find it strange why they don't talk about Mods*. I think there is a big "hesitation/retention" towards Mods by many People, and I can't really explain why.
To me, there is no difference between Official and modded Content aside from older broken mods and mods that are too OP (just OP is ok, since there is already OP in official stuff). What's the Difference between the Game Modes from NFP and the countless Mods that add new Mechanics to the Game? The former is praised by most people, but the latter is ignored or looked down upon. Which I find very strange, bc there are many Mods that are of much better Quality than Official stuff and add much better gameplay/replayability to the Game, yet people hesitate towards using them, and treat them as something that could break the game (where in reality many even fix and balance the Game). Also, many People complain a lot about Balance, representation and want more content, yet refuse to believe that what they are looking for already exists in Mods. They want Civ X or mutually exclusive Buildings, yet they don't care about mods that add them, but only want them if they are officially added by Firaxis. And some complain about replayability, yet they don't want to use mods to add that replayability. My Question is: But Why?
What have become of the Community that existed because of Modding? I think Civilization VI reached a point where it won't receive much official support, and where mods will be the only thing that breathes live into the Game. If you're not a mod user then I'm afraid there isn't much left to talk about, but if you're open for mods then you'll have plenty of new things to try, discuss and... more turns to play.
*Good Examples include: Urban Complexity, Grand Eras, City Lights, Monopoly++, Strategic Forts, Sui Generis, Real Natural Disasters, Movable Districts, Nomina, A Mountain is fine too, Civilizations Expanded...etc.
EDIT: This isn't just an Issue on CFC, but also observable on Reddit for example.