I got this questions recently:
“I’ve written 20 pages of a screenplay. Would someone accept just twenty pages? I just want someone to read what I’ve got and tell me if I have an idea, or if my concept is garbage. If it’s trash, I want to bag it so I can start thinking of something new rather than waste my time on a bad idea.”
You’ve got to finish your script before you can do anything. “Great ideas” are literally dime a dozen so it really does not matter if your concept is any good at this stage. What is worth gold in Hollywood is a solid idea that’s well executed. The only way to know if a script is well executed is to write a complete draft. If you keep jumping from projects to projects before finishing one you’ll end up with lots of unfinished projects. So my advice it to find an idea that you’re passionate about and write a complete draft. Then once you’re done with that draft find another idea your’re passionate about and write a complete draft of that, too. If you have passion for your story then it’s an idea worth writing, don’t worry about what other people say. The main point to all this writing is to get better at your craft. It’s unlikely that you’re first script (or second or third) is going to be well executed so it honestly doesn’t matter if the idea is any good either. Just put in the time and do the work and write your ideas into complete scripts.
I can tell you this about your idea, if it’s not worth it to you to write the entire screenplay, then it’s probably not an idea worth pursing. You don’t need an expert or industry insider to tell you that.