If I had a penny for every straw man argument. Who said anything about writing plaintext passwords to files - you just made that up?

Also you might not understand web dev 101. Every website including this one that uses HTTPS sends encrypted data, the password you enter in a text input is in plaintext. For the backend - as I said above, the server hashes it and saves the hash, never the plaintext password.

That's how it works - nobody said anything about "log files".