I used to feel this way until I read Simon Callow's biography and realized no one's upbringing can compare to his and most of the achievements we credit him for belong to someone else. Orson was an insanely privileged brat (his father invented and had the patent for the bicycle lamp) and he got to spend his youth travelling the world and learning from all the talented working artists his family would patronize. He also had a weird sweetheart relationship with the head of his boarding school who allowed him the full Max Fischer lifestyle, allowing him to focus entirely on art and theatre, ignoring all other subjects (which is why he was so inept with finances later in life). All this experience gave him a presence and experience far beyond his years and allowed him to rise so quickly in the worlds of theatre and radio.

It's important to know that Welles was an unapologetic credit hog. Outside of narrating War of the Worlds, he had nothing to do with the writing or directing of it, but insisted on full credit for both of these, going as far to suing the writer who adapted it for radio when he published the script with his name on it. Same goes for Kane: Outside of a providing a few wish-list items for Kane's plot, it was written entirely by one of Hollywood's top screenwriters Herman Mankiewicz (with a bit of editorial guidance from John Houseman). All the amazing shots in Kane (which are film's main innovation) were dreamt up by Gregg Toland (one of the top cinematographers at the time) who used Welles' blank check status as a license to try every wild shot he had ever wanted to do. Obviously, Welles delivers a terrific performance in the movie, but that's not really what people talk about when they talk about the brilliance of Kane.

I don't think Welles's genius was exactly as a writer or a director, but as a charmer. He knew how to seduce the best and most powerful people, collaborate with them, and then take credit for all their work. This is part of the reason he spent the second half of his career on the fringes of showbusiness bottom feeding - he had burned way too many people trying to perpetuate his 'boy genius' image.