I was looking back at the Dark Matter campaign awhile ago and felt the same way. The fun has been sucked out of conspiracy theories.
Even in the 1990s, Dark*Matter was pretty off-beam because it essentially "flipped the script" on stuff like the X-Files, without saying it or making it obvious by doing the following:
1) Has very dodgy far-right attitudes to less secretive government agencies - it's really mad with the ATF, for example (even though it admits it's not a conspiracy!). FEMA is 100% as evil as the wildest far-right conspiracies would have, literally a fascist organisation aiming to take over the world if gets the slightest excuse (they even use the word "fascist"), to take away all your freedoms and put you in a camp and so on. The CDC are evil in every way you can imagine, again in ways which reflect far-right paranoia, and infiltrated by evil feminists who are going to get rid of the need for men (The Amazons of the Gynarchy and no I didn't make that up lol). The UN and the Bilderbergers obviously get it as well, in a rather shocking way.
2) Making it so that organised, Abrahamic religion, was in general capital-G Good, and fighting capital E Evil in secret. This can be okay if done right and ambiguously/weirdly enough (c.f. the Charlie Parker detective novels), but this was unambiguous, and it was weird as hell, and now looks completely insane after, for example, various huge child-abuse cover-ups (real conspiracies). A particularly sick bit is when we hear about how the Catholic church works in secret to defeat evil literally "prevent[ing] paranormal disasters", and gives a list of what are to presume are these activities - the witch hunts, the inquisition, the brutal suppression of various pagan religions, fighting the "thugees" and the Boxer Rebellion, and so on. It's a mind-blowing section because it really seems to think this a good thing. Oh bonus there's an entire powerful good-guy-oriented magic set basically only for Abrahamic religions - they explicitly list out Christianity, Judaism and and Islam, no others - including various classic D&D Cleric-esque spells, where non-Abrahamic faiths get... voodoo and shamanism. It does largely skip Islamophobia at least!
3) Made the Satanic Panic real and justified, because in Dark*Matter, there is a huge, terrifying literally-Satanic conspiracy, called The Final Church, which the sourcebook for basically aligns with every wild far-right conspiracy theory, indeed, it's a very good match for an awful lot of Qanon stuff.
4) Uses a lot of "real-world" "conspiracies", including, I kid you not, the Freemasons (painted in a pretty dark light, which is weird because they're both real and largely harmless - basically just old-fashioned corruption/old-boys-network rather than a directed conspiracy), and even names real people who were still alive when it was out (like Buzz Aldrin, an alleged Freemason conspirator in Dark*Matter), which in a really gonzo and wild RPG might be forgivable, esp. if it was small press, but seem kind of screwed up in this context. The Final Church is also the name of a real-world group, and it has ripped from the headlines stuff like Aum Shinryko, which even in 1999, felt gross as hell.
5) Is super-duper orientalist and has a ton of racism which I'm not even going to start on because we'd be here all day - this is less of a flip on the X-Files (which has at least a couple of deeply racist episodes, one of which is also possibly the dumbest episode, and just reeks of "I wrote this whilst on coke") and more "the 1990s, man", but it's pretty goddamn cursed, and it's significantly more racist than one might expect even for 1998.
I could go on but even in 1998, Dark*Matter was a deeply dodgy and questionable take on conspiracy theories.
Now, in 2023? Every really far-right Qanon-adjacent conspiracy theory is 100% true in Dark*Matter, whereas in the X-Files or Conspiracy X, that generally isn't true - very few are - more are misunderstood that flatly true, or just misdirections from other stuff.
So let's not pretend Dark*Matter was a cool product from a cool time. It was a messed-up product from a messed-up time.