I was looking at the scripts in the build folder and found stubGenerator

Is this still of any use?

Running it in joomla 5 produces an file with just a single header line of <?php ?

Running it in joomla 6 produces an error

Symfony\Component\ErrorHandler\Error\ClassNotFoundError^ {#14
  #message: """
    Attempted to load class "CliApplication" from namespace "Joomla\CMS\Application".\n
    Did you forget a "use" statement for another namespace?
    """
  #code: 0
  #file: "D:\repos\j6\build\stubGenerator.php"
  #line: 51
}

enabling the bcompat plugin in j6 didnt change anything - can that plugin even do anything in the CLI?