I think the bottleneck you're describing isn't "writing" but creators who will be trusted with a $X0 million budget without excessive oversight.
Sorkin or Tarantino get the leeway to create something without executives second-guessing every little decision, most people, even very talented people won't.
There are tons of talented writers producing things, but in a less expensive medium. The cost to produce a novel is literally 0.1% of a Hollywood movie. There is a lot more freedom to work there than when you're spending tens of millions of dollars.
Sorkin or Tarantino get the leeway to create something without executives second-guessing every little decision, most people, even very talented people won't.
There are tons of talented writers producing things, but in a less expensive medium. The cost to produce a novel is literally 0.1% of a Hollywood movie. There is a lot more freedom to work there than when you're spending tens of millions of dollars.