Perhaps our legal system found that there is no evidence of libel and you are picking and choosing which legal decisions you agree with despite all being as part of the same system.

I'm no lawyer, but the fact that Elon got off on that just seems wrong. Elon's claims were completely made up and also specifically crafted to harm the victim's reputation with respect to the particular context of the accusation - baselessly labeling a man who risked his life to save children as a person that sexually abuses children. What a disgusting act. Elon is extremely famous, if that doesn't count as libel what does?

Elon's lawyers argued that it was clearly satire because it was so over the top he couldn't possible mean it, the same as when he made deliberate misrepresentations about selling the company in a naked attempt to manipulate stock prices.

Elon has very good lawyers.

Edit: nevermind. They withdrew the UK case and the one that went to court was in the US.

I'm not sure which case you're talking about. Trial was held in Los Angeles. https://www.bbc.com/news/world-us-canada-50695593

I'm actually unsure, is calling someone (let's say a private citizen rather an a celebrity) a pedophile based on flimsy reasoning illegal in the US?

It's considered "per se" defamation, meaning that the plaintiff only has to prove that the defamatory act occurred, not that any reputational harm actually resulted (the harm is presumed from the heinous nature of the defamatory statements).

Calling people rapists and pedos and getting a away with it is in my eyes very American.

If the CEO does this in a private conversation, as in you and CEO, I don't see how this could be libel.

I don't think tweets and newspaper editorials are considered private