At the very top of https://docs.python.org/3.9/library/os.path.html there is this section regarding str and bytes:

> The path parameters can be passed as either strings, or bytes.

They also accept path-like since Python 3.6, see https://www.python.org/dev/peps/pep-0519/ (Adding a file system path protocol). I'd add path-like to the list.

> Unfortunately, some file names may not be representable as strings on Unix, so applications that need to support arbitrary file names on Unix should use bytes objects to represent path names.

This is no longer true since Python 3.1 and https://www.python.org/dev/peps/pep-0383/ (Non-decodable Bytes in System Character Interfaces). I'd suggest to delete this.

> Vice versa, using bytes objects cannot represent all file names on Windows (in the standard mbcs encoding), hence Windows applications should use string objects to access all files.

This is no longer true since Python 3.6 and https://www.python.org/dev/peps/pep-0529/ (Change Windows filesystem encoding to UTF-8). I'd suggest to delete this as well.