No, it would be a conspiracy only they conspired to do so.
I don't think that's the case with most of them. There are a lot of movements coming from different backgrounds, believing in different things that are meeting at "it's not real, don't get vaccinated". The Bill-Gates-Wants-To-Kill-Us-people aren't conspiring with the Big-Pharma-Wants-A-Perpetual-Vaccine-Business-People, they just happen to come to the same conclusion ("don't do it").
From what little exposure I had to them, I think they're honest in their ideas. I believe they're wrong on most counts, but I don't think they're sitting at home scheming how to fool the masses. I'm sure there are some who seek to influence public opinion by spreading false narratives, but the large majority seems to just have lost pretty much all trust in Western governments and looks for alternative theories that explain the state of the world.
I think you've made a category error. We're not talking about the lost schmucks who've bought into this claptrap - we're talking about whose bright idea it was in the first place, and who's making an effort to spread it. Someone is providing those "alternative theories". You dig around a little and you find dubiously funded websites and media outlets pushing this stuff, as well as the more unsavory elements of media we call "mainstream". It's not nearly as organic as it seems, and we shouldn't let the bad actors hide behind social media as the scapegoat. "Astroturfing" is not new.
So, who benefits when Americans lose faith in their government?
Expecting such an outcome is starkly irrational. Its exact opposite is far more likely, as evidenced by the fact that we're already well down exactly that road to exactly that destination.
Why on earth would it? The government is the engine of social cooperation. Losing faith in it puts you on the road away from civilization, not towards.
If I look at the groups in America who appear to have lost faith in their government, I see a lot of groups - Proud Boys, antivaxxers, antimaskers, anti-CDC people - who could not be remotely categorized as critical thinkers. Their behaviors have caused a longer loss in personal liberty because the pandemic continues. And, to look at the Capitol insurrectionists - there's not much accountability.
I just don't think there's much evidence that losing faith in government leads to any of those benefits. And my experience tells me that it does the opposite.
> Someone is providing those "alternative theories".
I'm not sure they are. I mean, sure, for some things, there's likely someone somewhere making it up, but others just come to live by themselves.
A lot of them remind me of the preppers. They also have plenty of scenarios and end up in similar places on practical questions. And companies around that also were created or took up some of the content to market to them. This might be the same here: websites trying to attract these people for other reasons instead of those websites being the source of the ideas.
Since a lot of it is happening online, I guess it should theoretically be/have been visible, do you know of any reports that trace it back to those who created the different conspiracy theories?
Do you also believe that correlation implies causation? Because it's practically the same thing. A conspiracy requires that people conspire, i.e. coordinate. Correlated action is entirely possible without conspiracy, as is evident during any traffic jam or holiday shopping rush.