> Funny thing about conspiracy "theory" is that a lot of the time the theory turns out to be true.

I would love to see any sources on this claim.

A lot of "conspiracy theories" end up being true in some vague way; "the NSA is spying on all of us", yeah, that was true. The NSA is using satellites to read our thoughts? Not so much. Still, people will point to things like the Snowdon leaks to prove that the US government cannot be trusted (which is true) and therefore all the other claims that people make are also true.

The reality is that most conspiracy theories are impossible, either from a technical sense or a logistical one. The extreme examples, like "the earth is flat and the governments are hiding it" or "COVID isn't real and the vaccine is going to kill everyone but every government and doctor on earth is secretly in on it" get shrugged off as "well, not THOSE ones obviously", but most of the rest I've ever seen are also completely unbelievable.

Here's the thing: anyone can come up with a theory and stitch together the most circumstantial "evidence" to "prove" it, combining misinformation, misunderstanding, and misrepresentation to produce something that feels like it could be true on its face if people don't do any real digging, and most don't. I've yet to see a "conspiracy theory" backed by any actual hard evidence; they seem to entirely spring from an overactive imagination and are then "justified" and "proven" by finding other facts to fit the narrative retroactively.

Is there clandestine activity? Absolutely. Are there groups of people trying to manipulate situations and lie to the public for their own gain? Almost certainly. Do people with unsourced, unproven conspiracy theories make it easier for governments to get away with whatever they want because the rampant proliferation of crackpot theories allows for a convenient smokescreen whenever the truth starts to come out? Also yes.

Even if only 10% of conspiracy theories are true, which they are not, the people repeating them do more harm than good by doing so in a way that discredits themselves and others.

The idea of the conspiracy theorist is a hyperbole fabricated in the public mind by the "almost certain" activity of "groups of people trying to manipulate situations and lie to the public for their own gain". It's not that a reasonably plausible theory being discussed will logically lend credence to less plausible and unrelated ones, it's that the public is conditioned to believe that it does. That way, public discussion of any conspiracy in theory is verboten by the "conspiracy theory" thought-stopper, regardless of the theory's plausibility. Because, as you say yourself, it makes it easier for conspiracy in practice to go unnoticed in the public sphere. From a Bayesian perspective, the problem is less likely caused by the crazy people who have a poor grasp on reality than the people who not only have a reason to emphasize the crazy people (because it de-emphasizes themselves), but also the means.