Especially the ones about a certain felon

But that's the point. The Onion tries to write real-sounding headlines, and c/nottheonion is for real headlines that sound particularly unbelievable.
- I don't think the Onion was originally meant to sound real though. It's just gotten that way because of how absurd our actual current events are.
  Similar to how the "Weekend Update" segment on SNL used to be primarily joke headlines (with the exception of the OJ Simpson trial), but now they can literally make an entire segment using actual footage from a Trump rally.
- No.
  The Onion, and parody in general, aims at being an exaggerated caricature of the truth, something that has a kernel of plausibility in its core, but has elements or scale that is blown out to ludicrous extremes, or is framed in an unexpected way such that it inherently juxtaposes a social approach to a certain realm of topics with another realm of topics, exposing a double standard that larger society has.
  Parody is not just 'plausible, but fictional.'
  That would ... just be a hoax, mis or disinformation, or realistic fiction if not presented as news.
  ... The fact that it is so difficult now to tell many parodies from a person's or group's actual actions or statements, or complex events... this speaks to an increasingly extreme world, it speaks to ... basically the death of a general concept of 'normal' from which parody can grow.
  
  Onion isn't parody, it's satire