Does this do anything that the builtin argparse library https://docs.python.org/3/library/argparse.html doesn't? Seems it just turns it into decorator syntax.
Plus it comes with some useful utilities you might need in a cli to show a progressbar, display color, open test in a pager/an editor etc.
The official doc is really nice and gives it more justice than this blog post: https://click.palletsprojects.com/en/7.x.