Most screenplays don't fail because the idea was bad. They fail because the writer stalled out somewhere around page 40, staring at a scene that refuses to move, and never opened the file again.
The blank page isn't the real problem
Everyone talks about "beating writer's block" like the hard part is starting. It usually isn't. The hard part is momentum — getting from a scene you can picture clearly to the next one, over and over, for ninety pages.
That's where an AI writing partner earns its place. Not to write the movie for you, but to keep you moving: turning a rough idea for a scene into a first pass you can react to, reshape, and make yours.
Use it to draft, not to decide
The scripts that read like AI wrote them are the ones where a writer accepted the first output and moved on. The ones that work are the ones where AI got the boring part — getting words on the page in correct format — out of the way, so the writer could spend their energy on the part only they can do: the specific line, the specific silence, the specific choice a character makes.
Treat every AI draft as a placeholder for your actual scene, not the scene itself.
In practice that means: describe the scene in plain language, let the tool produce a formatted first pass, then rewrite the dialogue until it sounds like your characters and not like anyone's characters.
Keep the story connected as you go
The other place drafts die is continuity — losing track of who knows what by scene 30. A workspace that keeps your scenes, characters and screenplay in one place (instead of scattered across a dozen documents) removes a lot of the reason to give up midway.
Write the messy version first. Fix it in the next pass. Just don't let the first pass take three months.