>I disagree that they're good at writing compilable code
That was never part of the discussion, because as explained several times now it is irrelevant in this case. The existence of the original binary means all you need to do is match up things, which can be automated completely.
The problem is readability. No one in his right mind would call what they generate "C++". Mine still interjects assembler from time to time (and not the new version that GCC supports, but the older MSVC style) .
LLMs absolutely do not help with the generate working code part, because this is an exact problem that doesn't need nor benefit from an LLM (other than maybe automating stupid iteration?). They can help with the readability part, because here once you already have a working skeleton it doesn't matter that much if they make mistakes, as it is easy to detect.
If what you said was true, the projects mentioned above wouldn't have needed years of arduous work before the age of LLMs came to be.