This seems to be a Thing with some child celebrities. The kid who played Matilda is like that too. She complains all the time about how much she hated it but the only reason anyone gives her the attention she craves is because she was in a couple popular movies in the 90s. A lot of child actors, most of them, end up moving on to normal jobs, whether they want to or not. The kid from Hook got a law degree, disney kids went on to be a marine biologists, photographers, lawyers. church music directors. But Wil and Matilda are in that pathetic place where they say they hated their childhoods, but also refuse to move on and do anything meaningful as adults.
This was even something that happened with Christopher Robin who's considered the first child celebrity. He was conflicted by how much he loved the privileges and positive attention, but hated any of the downsides or that he was still defined as an adult by a childhood "character". He wanted to succeed on his own as a writer without his dad, but in the end just wrote a long boring ass autobiography and the only reason anyone bought it was because he was "Christopher Robin" in his dad's books. Kind of a rich kid thing, too, I guess.
Wil wants the success and attention but has to keep coming back to Dad (goodwill from his childhood roles) to open his wallet or use his connections for whatever's next--why so much of his adult work is scifi or even directly Star Trek related and why *so much of his autobiography focuses on his childhood. He doesn't have the talent to do it on his own, or the humility to get a "real" job.
It also reminds me a little bit of ex-Whatever types who never grow up and move on past the rejection phase. Ex-Mormon, Ex-Jehovah's witnesses, raised by narcissists, etc. They blame everything, past and present, on their experiences as a child to the point it's their whole personality, instead of healing and starting a new life free of it.