The first programs were written in binary/hexadecimal, and only later did we invent coding languages to convert between human readable code and binary machine code.
So why can’t we just do the same thing in reverse? I hear a lot about devices from audio streaming to footware rendered useless by abandonware. Couldn’t a very smart person (or AI) just take the existing program and turn it into code?
It’s not impossible just difficult.
You could use a tool like ghidra for example to study a program and workout what everything does.
https://ghidra-sre.org/