A movie director can see the sets with their own eyes. But you can't see the state of a software codebase without reading and understanding the code, and the most surefire way to do that is to try to write something, even just documentation.
You don't assess the state of your software by walking around the office and looking at hands on keyboards. You look at the codebase.
I don't know that much about movie making, but my understanding is that there would be managers and/or leads within each specialty, who are (among other things) managing the interaction between their specialty and the director / producers.
That seems pretty comparable to what's being discussed here.
Many directors started in other roles in the movie industry, typically as writers, PAs, or other subspecialties. Chad Stahelski was a stuntman and stunt coordinator before he started directing John Wick, and it really shows.
I think the clear distinction is between someone who understands a part of the job, and someone who is good at part of the job. If you don't understand how costuming works, as a director, you're going to have a hard time getting good costumes, but by no means does that mean you're able to pinch hit in that role. I personally believe that it's difficult to replace hands on experience as a way to truly understand something.
In software engineering, I think there's a huge gap between managers who worked in some other industry and transferred over, versus having previously been an engineer, even a mediocre one. Knowing how the sausage is made is hard to replace.
Like imagine you were a coding manager 10 years ago with AI experience. Sometime over the last 10 years your team does AI infra. You, as a manager and as an IC, have zero AI experience (you've never trained a model, never used a trained model, never using any of the various AI frameworks). Are you still okay to manage this team or should you be replaced with someone who does have that experience?