I taught an entry-level programming class in a university setting. There were weekly programming practice "labs" and a more involved independent project with several check-ins with me over the semester.
I gave an open-book final exam that asked students to write a for loop on one of the questions. I would say around 20% bombed the question despite the very book sitting beside them having a chapter on looping. With examples.
After the class ended, I ultimately concluded a non-trivial number of students probably didn't do any of their own coding during the course. I'm pretty sure I have worked with at least two or three people in coding positions who couldn't actually code and relied on outside (spouse? out-sourced?) support.