Totally agree that plain header files have many issues, and they are a common source of headache, but can someone explain to me why replacing plaintext, greppab

Totally agree that plain header files have many issues, and they are a common source of headache, but can someone explain to me why replacing plaintext, greppable header files with a seemingly very fragile/unportable binary format is a good idea? Surely I must be missing something? I get the sense that they tried to fix complex issues of header files by introducing more complexity. Is it assumed that new tooling will hide this complexity? All genuine questions, I haven't tried out C++ modules myself at all yet.