That's a fair question, but we do live in a surprisingly secretive society. I think that shifted over a lot during the Cold War period. It became acceptable to hide large sections of public spending from the public.

We also live in a corrupt society and occasionally that emerges as a scandal.

Certain secrets are kept better than others. Now and then real conspiracies do become public knowledge like the Tuskegee Experiment or Scientology's infiltration of parts of the US government.