The other big thing that is a barrier to true investigation is the “government would never do that” idea.
Just look at how seemingly unrelated people and agencies colluded to get rid of Trump, without visible command structure or instructions.
Then rethink JFK.
I've read a lot about William Donovan, founder of the OSS (forerunner of the CIA) in WWII, and have concluded that, while the man may have been a genius in many ways, he either had a blind spot to, or was willing to overlook the enemy within for war time expediency.
IMHO, Donovan was (like Kipling in many ways) a 19th century man operating in the 20th century. To be sure, he was something of an elitist, but not so much in the way we use the word today. His parents were relatively successful in spite of much anti-Irish sentiment, and that, combined with his rigid Catholic upbringing, I think filled him with a sense of noblesse oblige, and the spirit of Luke 12:48.
Donovan was an American patriot, and IMHO, naively could not conceive of any of the upper classes not being patriots. As such, by the time he was tasked by FDR to build and run the OSS, he recruited heavily from the Ivies wanting only, "the best and brightest," unaware of how much they had been infiltrated by the left during the 20s and 30s. This seeded the nascent US intelligence community with many who had an entirely different perception of what their elitism meant. Then, when the CIA was officially established, Truman cut Donovan out of the loop entirely (because he was a republican), and the wheels were put in motion bringing us to where we are today in the intel community.
Just my $0.02