I think the belief in conspiracy theories around secret societies probably comes from an misunderstanding when the term 'managerial elites' is used.
These aren't people meeting with funny handshakes, but it's literally in plain sight that there are the likes of the WEF, Gates, Blair and how things like the EU and OECD work that the group of people that have a meaningful input in the direction a democracy goes in is far smaller than the number of people who actually vote.
More simply, when your average person is so far down the social strata, they can only imagine what's at the top.