I mean, that's kinda on you, though, right? If you're just going to poke at your code until it works, that's your choice, I guess, but I wouldn't call it good programming.

The point is that it's reasonable and possible to predict the compiler's assembly output from high-level source. Maybe each individual can't do it, but they could, with a little learning.

With LLMs, you just can't predict the output for a given prompt, and can't predict how changing that prompt will change the output (or how much it will change the output). Even the people who build and work on LLMs every single day and know them intimately can't.