1. It is great to see an effect of your thoughts, like something happening in the real world. 2. Coding offers a feeling of perfect control due to the deterministic nature of code.
I would argue that 1 is still the case with LLMs, and 2 was always just 95% true, never 100%, because of oversights, bugs in libraries, and what have you.
So what actually decays is maybe not so much the feeling of self-efficacy, but the feeling of control, and even this is a gradual change. Perhaps it would be less unsettling if it didn't happen at the same time as a potential loss of control in other areas: career, salary, mode of working etc.