Compilers also had bugs, so we still had to debug the assembly to understand how to fix the problem. Nowadays, almost nobody has to resort to those steps, except of course compiler developers. But that is just a testament to the quality of compilers.
Comparing LLMs to compilers is a take I often see, but I am not sure the comparison quite holds. The problem is that LLMs are inherently non-deterministic, so we always get a different output on the same prompt.
Maybe if LLMs are powerful enough it won't matter. I doubt it but we will see.