Bill Cooper's Mystery Babylon radio series from the late 90s is archived online and was intended to act as an in depth primer >40 hours. Quigley's books are freely available from his wikipedia page:

https://en.wikipedia.org/wiki/Carroll_Quigley

It's relatively harmless and in good fun. Saying there is nothing there betrays ignorance on the source material. If anything I'm prone to believe some of the conspirators are behind the dissemination of the theories, if only to draw a little attention and recognition from a largely disinterested general public.

You work for money right? How does this scale?

Its not like wealthy, powerful, privileged people could actually get together and forge some kind of sinister plan to expand their wealth power and privilege - Right?

If that would be possible there would be clear signs of it all over the world. It would require great effort not to notice it.

They pretty obviously can and do. However, explanations of world events quickly get ridiculous when it's posited that there's one such group in charge rather than multiple ones in conflict/competition.

In an interview RAW was asked what could be the cause of the popularity of the Illuminati conspiracy. His answer was three-fold:

There is too much information nowadays. Life's truths used to be simple: USA good, Russia bad. You adopted the political views of your parents. Men worked and women stayed at home. Your favorite news station was always right. Too much information and fast change leads to a cognitive overload. One protection mechanism to not lose touch with reality and filter the large amounts of information, is to create very simple truths. One of these truths is that there are rich powerful people behind the curtain controlling everything.

Second, with the rise of the internet and search engines, it means that if you have an idea of a conspiracy, no matter how far out, there is likely a website already documenting it. Everyone can feel like an expert after a few hours of internet research. The barriers to publish your views on a conspiracy have vanished: always resulting in a few websites out there that confirm your hunches. For instance, if you perform research on vaccines, and start out as biased against them, you will likely stumble on a lot of a websites that tell you exactly what you want to hear: vaccines are bad and used by the governments to control their people.

Finally, there simply are a lot of rich and powerful people conspiring behind the scenes to move society in a certain direction. Just one example was the P2 lodge [1] in Italy, also called a "state within a state". It is unlikely that the queens of this giant collection of ant hills we call humanity have stopped conspiring. It just happens under a different name than the Illuminati. Symbolically, the Illuminati stood for rebellion against the church and royalty, in favor of monetary power and reason. That's a role for capitalists and scientists now.

[1] https://en.wikipedia.org/wiki/Propaganda_Due

And if I may be so bold to add a fourth reason, gossip has always been a form of social currency. It feels good to be privy to secrets and have information that other people do not have. Gossip on the internet is a supercharged version of this, the best gossip going viral. Couple this with an increased access to information and gossip by the middle and lower class: Old governments were much more able to keep their secrets from the middle and lower class. The media was much more controlled by those in power. Journalists in my country still refuse to write about certain secrets and conspiracies concerning politicians and royalty. But plenty of bloggers do. This reinforces the beliefs in conspiracies, especially if it later turns out to be validated by the old media.

All you are really saying is, people belive in something (because its hard to believe in nothing). That doesn't explain the type of believe they hold.

While anarchy has to be the default assumption, its hardly the commonly accepted notion of the status quo. It seems much more comfortable to assume that everything is in order of a personally profitable higher purpose.

Whereas conspiracies are usually attributed to a lack of moral and socially intollerable consequences.

I mean, how are conspiracy theories comforting instead of scary? Instead, conspiracies and anarchy alike are scary because of a lack of cooperation.