Thanks to a youtube follower who asked us to create a recaptcha solution for Joomla 4 login page, you will, shortly, have the basic security every login page should have: a captcha field. Why? Because you may find yourself invaded by unwanted messages and/or fraud/abuse you have no idea where they came from. That is why the motto of google recaptcha is clear: reCAPTCHA protects your website from fraud and abuse without creating friction.
I have no idea why the Joomla developers have not, by default, added recaptcha to the login forms as they do for the user registration form.
This tutorial must be applied by a web developer with good experience using at least Joomla 3 CMS